When you start cultivating cannabis indoors, whether the beginning of a lifetime endeavor or a seasonal hobby, there are many initial hurdles to overcome to give your plants the environment they need to thrive. Knowing where to start can be a challenge. Advice on building an indoor grow depends on your techniques and setup, but most importantly, it depends on your grow location.
In this article, we’ll review the ins and outs of cultivating an attic or loft grow room to ensure you know everything needed before starting. Some homes and living situations don’t include an attic or loft, but when they do, the space can be perfect for setting up an out-of-the-way and secure grow. It can be tempting to rush into your first grow once you’ve found unused space in your attic, but a little caution and planning before your attic grow room is built will reduce stress down the road.
The specifics of growing weed in an attic
In cannabis cultivation, so much depends on your environmental variables and the grow location. In some homes, the attic may go unused and could be the perfect hideaway spot to put a few cannabis plants where they won’t interfere with daily life.
That being said, in general, growing cannabis in the attic will require cultivation knowledge outlined in our Grow Bible. This article will examine the exceptions and specifics of an attic grow room to ensure your horticultural efforts succeed. When you know how to set up a low-budget grow room, you can keep things at a low cost and relatively simple or go all out and automate your attic grows.
Can I grow in the attic?
Of course! The attic, if available, can be used to cultivate like most other open areas and closets in your home. Plants can be left alone easier up in an attic where only the grower may interfere and know about them. It may even provide enough space for a fairly large grow that cannot fit elsewhere in your home.
The attic is often forgotten and used to store old items and decorations. Building a grow room in an attic is the perfect way to utilize your space and keep it from getting dusty and forgotten while conveniently staying near your plants and ensuring others cannot access them.
The pros and cons of growing cannabis in an attic
We’ve established that the attic could be a great place to grow cannabis, but let’s break it down here.
The pros of using your attic:
It utilizes unused spaces in the home, keeps your grow nearby and ready to tend, and can be hidden from guests and other people in the house if needed. Your attic grow room can be as simple as a small grow tent and scale up from there.
The attic is a low-cost entry option for a grower to experiment with cultivation on a small scale. Experienced growers can turn an attic into a perpetual grow by using exposed studs, floor joists, and more to construct the grow room of their dreams.
The cons of using your attic:
Accessing your grow in the attic can be challenging. For example, in my home growing up, a three-part folding ladder needed to be pulled down from the garage ceiling to reach the attic. This can wreck the convenience factor for you and add to the struggle of home growing.
The other major issue in an attic is temperature control, depending on your home and situation. Most homes have an insulation layer on the attic floor to keep the rooms below at the correct temperature. This means the attic is swinging in temperature with the outdoors and is not environmentally controlled. If you have good weather, the attic will be temperate, but your plants will experience outside temps even when it’s cold or hot outside.
Flooring stability and utility access can also be questionable in attics, not to mention the varying ceiling height some attics introduce to the situation.
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Things to consider when starting an attic grow room
The cons listed above are the first things to keep in mind when constructing an attic grow. The accessibility of the attic, the stability of the flooring in the attic, the insulation or lack thereof in the attic, and utilities access are the big four that come next. This is before potential height constraints due to sloping roofs.
If you live in an area with heavy snow and ice in the winter, you may want to consider that your grow will most likely heat up a patch of your roof and melt said snow and ice. A friend of mine had this happen in Minneapolis, Minnesota and had to take his grow down to maintain privacy. Driving home and realizing every house is snow-covered, but yours is definitely a concern.
However, it’s the opposite problem in the desert, with attic temps rising to over 100 degrees and higher on hot days.
Potential dangers of growing in the attic
There are unique dangers to remember when cultivating in an attic; the first is the flooring. Many attics have no flooring. Do not set up an attic grow, thinking you will hop across the ceiling beams. A fall or slip can send you through the ceiling of your house into the room below, which may be a minor sheetrock repair or a major trip to the hospital. Consider installing proper flooring to support you and your attic grow room equipment.
Next would be the potential for leaking and spills. These are not wanted in any grow setup but are particularly dangerous in an attic since home wiring and electricity can be run through the ceilings. If water is spilled or leaked in the attic, it can cause electrical issues or contribute to mold and other structural issues that homeowners want nothing to do with.
In other words, the attic was not designed to handle water and humidity. Plan accordingly by setting redundant safety measures like a tarp under the grow tent to make 100% sure you aren’t impacting the structural or electrical integrity of your home while growing.
Fire is always a danger to be aware of when cultivating anywhere. It’s also true in an attic. When building a grow room in an attic, choose the right equipment. Pay careful attention to grow lights. They generate additional heat, making it harder for your grow room to reach its target temps. You can use air-cooled lights and, in general, equipment with low heat output and optional safety features to shut down in case of overheating to get around this.
You don’t want to introduce sparks or additional heat in the attic surrounded by your home’s wood framing and insulation. Be smart. The reality is certain attics are just not safe for cultivation, especially those with loose insulation, no flooring, and limited headspace.
Climate control issues specific to attic grows
With the dangers accounted for, we can discuss the next challenge in attic grow rooms: climate control!
Homes are built to control the environment within the home; this rarely includes the attic. Most heat generated in the attic will rise and be lost through the uninsulated roof, and the attic will be stuffy and hot when the sun is high. This can create a range of different climate-related problems.
You can address this. First of all, reduce the space you have to environmentally control by growing in a tent. If you want an open room concept in your attic, you’ll need a higher budget and insulation (see below). Heaters can help with the cooler temps, while fans and air ventilation can assist in the heat.
You can also try pulling air into the attic grow/tent from the home and not the outdoors. This may require some light HVAC work and creativity, but pulling the air from your home will give your plants a source of fresh air that is much closer to your target temps. Air pulled from within the home is also richer in CO2 (thanks to our exhalations), supplementing the environment in your attic grow naturally.
Your ventilation out of the grow should intake air from outside. Do this stealthily by running it under the eaves of your home where it isn’t visible from the outside.
The last thing to note and recommend is an environmental controller. Sure, you can grow without closely monitoring your grows, but the location and unique situation of growing in an attic really make environmental controls preferable. Being able to look at a controller or app on your phone for quick peace of mind will save you many trips to the attic and potentially save your grow or home if disaster strikes.
Environmental control app running on a smartphone
Should you insulate your attic when you want to use it as a grow room?
This is a difficult question to answer without knowing your cultivating goals and unique attic setup. Basically, it is not required, but it is generally a good idea. If you can insulate the attic, it will almost always be worth the effort.
Having temperature and humidity under your control is the name of the game in indoor cultivation. Growing in uninsulated places just makes that harder. You can use insulation boards or a myriad of other ways to formally and legitimately insulate your attic. Install proper flooring while you’re at it.
At a minimum, consider insulating part of the attic by creating a more controlled space within it. That process is more like building your own grow tent once you choose the space.
For those on a budget, growing in a tent placed in the attic accomplishes the same goal of creating a smaller space. If you have the luxury of a huge attic, you should insulate. Those lucky enough to have large attics could set up a top-of-the-line grow with the right tech and budget. Those with small and constrained attic spaces should be creative but always keep fire and water risks in mind.
Mistakes to avoid when growing marijuana in the attic
Don’t fall through the ceiling, and don’t melt the snow and ice off your roof in the winter. But seriously, be careful when growing in the attic; it introduces a lot of failure points that don’t exist when growing somewhere else, like a spare room or the basement.
You also want to avoid running your electrical off an extension cord running back into the house. Don’t do this. Contact an electrician to install a proper power supply to your attic safely. If you already have a power outlet in the attic, it may still be worth having somebody test it, as attics tend to get dusty and forgotten over the years. If you do this initially, you’ll be off to the races cultivating in your attic grow with much less stress. Remember, an ounce of prevention is a pound of cure.
If you want to learn more about growing marijuana indoors, please sign up below to get our grow bible in your mailbox!
With all of the previously mentioned notes and suggestions in mind, we can talk about watering and cultivar selections when building a grow room in an attic. Hydro and automated watering systems are great in the attic because you can rely on the system.
That being said, have your redundancies in place and keep small water reservoirs in safe places like plastic tubes where leaks will not affect the attic or your home. If you can swing it, having a water connection run up from the house into the attic would be ideal, but in most cases, you’ll be carrying water for the grow upstairs.
Plan this out; water is heavy and can throw you off balance when climbing a ladder to the attic. Consider a pulley system or a small amount of rigging to move things up and down quicker if this is a permanent space for you.
When selecting cultivars, it’s always important to consider your space; it rings true again for the attic. You do not want to be stuck with a leggy sativa landrace reaching for the stars in the attic when you have a limited headspace of five feet. That will be an unhappy plant, for sure.
Choose cultivars that will match the profile of your grow. If you want that leggy sativa, employ low-stress or high-stress training to shape and nurture the plant into the shape and size you need to achieve your goals and stay within your constraints.
Noise may also be a concern for the attic, depending on which rooms of the house your grow is on top of; ventilation fans, pumps, and heaters may all add a certain “white noise” vibe. If this is too noticeable, you may be able to find some stealthier equipment options or consider insulation, as it will mask some of the sound.
Grow tents specially made for your attic grow
Let’s talk about using grow tents in an attic grow room build. You could grab a micro grow box or a 2×2 tent and run something small. Micro grows will reduce the stress around the flooring, insulation, and more. In general, a micro grow box is a great place to get started and stay stealthy.
But if you’d like to really maximize the space, you’d go taller. However, the ceilings of attics are not exactly easy to work with; some have a sloped roof, limiting the amount of full space available. Luckily, grow equipment companies are now making grow tents with this attic shape in mind.
Example of an attic grow tent
These tents help solve some of the insulation, temperature, and water leakage concerns by containing your grow and giving you as much height as you need in the center while accommodating sloping roofs. Here’s one example of a ‘loft grow tent’; it gives you more room for hanging equipment and more space for air ducts, fans, and lights.
You could also start with a grow tent, then kit out your attic to support that sized tent to avoid over-insulating and retooling your attic space. This can also help visualize the needed ventilation and even test the temperature swings before starting.
Final thoughts:
In summary, an attic grow room has serious potential for home cultivating, but there are a whole lot of concerns and issues to go with it.
If you are lucky to have an environmentally controlled attic, then by all means, it is the perfect spot to grow. But if you have an unfloored attic that is full of insulation, your work may be cut out for you to prep the space.
I personally would prefer to grow in locations I can reach without climbing a ladder and not worry about structural and electrical issues due to my attic. But I definitely see the value and the security provided by attic grows; they can be extremely stealthy if needed. If you have the space to try an attic grow, consider the pros and cons and weigh them against growing in your basement or spare bathroom/bedroom before digging in.
Cannabis can thrive where you want it to with the right care and attention to detail. Remember, cultivation involves continuous learning and incremental improvements; the only way to start that journey is to pop some seeds and give it a try.
Want to do more research first? Sign up for our Grow Bible and review our extensive library of articles anytime you have a question. If you have any stories about your attic grows or comments on best practices when cultivating in an attic, add them below.
Optimizing Your Grow Room Setup for Maximum Yields; In the ever-evolving world of indoor gardening, achieving maximum yields from your grow room setup is the ultimate goal for many cultivators. Whether you’re growing for personal use or running a commercial operation, understanding how to optimize your grow room setup can make a significant difference in the quantity and quality of your harvest.
From lighting and ventilation to nutrient management and plant training techniques, every aspect plays a crucial role in maximizing yields. In this comprehensive guide, we’ll delve into the key factors and strategies for optimizing your grow room setup to achieve bountiful harvests.
1. Choosing the Right Location
Before diving into the technical aspects of your grow room setup, it’s essential to select the right location. Ideally, choose a space that offers ample room for your plants to grow vertically and horizontally. Ensure the area has access to electricity, adequate ventilation, and is easily accessible for maintenance tasks. Additionally, consider factors such as temperature, humidity, and light exposure when selecting the location for your grow room.
2. Lighting
Lighting is one of the most critical factors influencing plant growth and yield in indoor gardening. Choosing the right lighting system tailored to your specific needs is crucial for optimizing yields. High-intensity discharge (HID) lights, such as metal halide (MH) and high-pressure sodium (HPS) lamps, have long been popular choices among growers due to their efficiency and effectiveness in promoting robust plant growth during both vegetative and flowering stages.
However, light-emitting diode (LED) technology has emerged as a game-changer in recent years, offering energy-efficient lighting solutions with customizable spectrums to meet the unique requirements of different plant species and growth stages. LED grow lights produce less heat, consume less energy, and have a longer lifespan compared to traditional HID lighting systems, making them an increasingly popular choice among growers aiming to maximize yields while minimizing operational costs.
3. Ventilation and Air Circulation
Proper ventilation and air circulation are vital for maintaining optimal growing conditions and preventing issues such as heat buildup, humidity fluctuations, and the spread of pathogens. A well-designed ventilation system should include exhaust fans to remove stale air and excess heat, as well as intake fans to bring in fresh air and maintain proper airflow throughout the grow room.
Installing oscillating fans strategically within the grow room helps improve air circulation and prevents the formation of microclimates, ensuring uniform distribution of temperature and humidity levels. Additionally, carbon filters can be incorporated into the ventilation system to eliminate odors and purify the air, especially in enclosed indoor environments.
4. Temperature and Humidity Control
Maintaining the right temperature and humidity levels is essential for optimizing plant growth and maximizing yields. Most plants thrive within a temperature range of 70°F to 85°F (21°C to 29°C) during the day and slightly cooler temperatures at night. However, specific temperature requirements may vary depending on the plant species and growth stage.
Similarly, controlling humidity levels is crucial for preventing issues such as mold, mildew, and pest infestations. Aim for relative humidity levels of around 40% to 60% during the vegetative stage and slightly lower humidity levels (around 40% to 50%) during the flowering stage to minimize the risk of bud rot and other moisture-related problems.
Utilizing dehumidifiers, air conditioners, and humidifiers can help regulate temperature and humidity levels within the grow room, ensuring optimal growing conditions throughout the entire cultivation cycle.
5. Nutrient Management
Providing your plants with the right balance of nutrients is essential for maximizing yields and producing high-quality harvests. Hydroponic systems offer precise control over nutrient delivery, allowing growers to tailor nutrient solutions to meet the specific needs of their plants at each growth stage.
When using soil-based growing mediums, selecting high-quality organic fertilizers and supplements can help enhance soil fertility and promote healthy root development. Regular monitoring of pH and nutrient levels in the growing medium is essential to prevent nutrient deficiencies or imbalances that can adversely affect plant growth and yield.
Implementing a feeding schedule based on the nutritional requirements of your plants and adjusting nutrient concentrations as needed throughout the growth cycle ensures optimal nutrient uptake and maximizes yields.
6. Plant Training Techniques
Employing plant training techniques such as topping, pruning, and low-stress training (LST) can help optimize light penetration, airflow, and overall canopy structure, resulting in increased yields and improved bud quality.
Topping involves removing the apical meristem (main stem) of the plant to encourage lateral growth and the development of multiple colas, resulting in a more bushy and productive canopy. Pruning involves selectively removing lower foliage and non-productive branches to redirect energy towards the growth of larger, more robust buds.
Low-stress training techniques such as bending and securing branches can help create an even canopy and promote the development of multiple bud sites, maximizing the potential for higher yields. Additionally, techniques such as defoliation during the flowering stage can further improve light penetration and airflow, leading to denser, more resinous buds.
7. Monitoring and Maintenance
Regular monitoring of environmental conditions, nutrient levels, and plant health is essential for identifying and addressing potential issues before they escalate and negatively impact yields. Invest in quality monitoring equipment such as pH meters, EC (electrical conductivity) meters, and thermohygrometers to keep track of essential parameters and make informed decisions regarding nutrient management and environmental control.
Maintaining cleanliness and hygiene within the grow room is also crucial for preventing the spread of pests and diseases. Regularly sanitize equipment, sterilize growing containers, and remove any dead or decaying plant matter to create a healthy growing environment for your plants.
In conclusion, optimizing your grow room setup for maximum yields requires careful consideration of various factors ranging from lighting and ventilation to nutrient management and plant training techniques. By implementing the strategies outlined in this guide and fine-tuning your cultivation practices based on the specific needs of your plants, you can unlock the full potential of your indoor garden and achieve bountiful harvests year-round. Remember to stay vigilant, adapt to changing conditions, and continuously strive for improvement to ensure consistent success in your indoor gardening endeavors.
Cannabis cultivation is an art that demands meticulous care and attention to detail to avoid Common Pests and Diseases in Cannabis Plants.
Among the challenges that growers face, pests and diseases rank high on the list of concerns. From tiny insects to microscopic pathogens, these threats can wreak havoc on cannabis crops if left unchecked. However, armed with knowledge and proactive measures, growers can effectively prevent and manage these issues.
32 oz bottle shown
In this article, we’ll delve into some of the most common pests and diseases in cannabis plants, along with strategies for prevention and treatment.
Common Pests
Spider Mites: These minuscule arachnids are a nightmare for cannabis growers. They feed on plant sap, causing yellowing leaves, webbing, and stunted growth. Spider mites thrive in warm, dry conditions, making indoor grows particularly vulnerable. Regular inspection and the use of predatory mites or insecticidal soaps can help control infestations.
Aphids: These small, soft-bodied insects suck sap from cannabis plants, leading to distorted growth and the spread of viruses. Aphids multiply rapidly, making early detection crucial. Natural predators like ladybugs or lacewings can help keep aphid populations in check, while neem oil or insecticidal soap can be used for control.
Fungus Gnats: These tiny flies lay their eggs in moist soil, where the larvae feed on plant roots. Overwatering and poor drainage can exacerbate fungus gnat problems. Yellow sticky traps can help monitor adult populations, while reducing watering frequency and applying beneficial nematodes to the soil can control larvae.
Thrips: Thrips are slender insects that damage cannabis plants by sucking out chlorophyll, causing silver or bronze streaks on leaves and bud deformation. They can also transmit viruses. Insecticidal soap or neem oil can be effective against thrips, along with maintaining a clean growing environment to discourage infestations.
Whiteflies: These tiny, moth-like insects feed on plant sap, causing wilting, yellowing leaves, and the spread of mold. Whiteflies can quickly become a nuisance in indoor grows, where they thrive in warm temperatures. Yellow sticky traps and insecticidal soap can help manage whitefly populations, while introducing natural predators like Encarsia formosa can provide long-term control.
Common Diseases
Powdery Mildew: This fungal disease appears as a white powdery substance on leaves and stems, eventually causing them to wilt and die. Poor air circulation, high humidity, and crowded plant spacing can promote powdery mildew. Prevention involves maintaining proper ventilation, reducing humidity levels, and using fungicidal sprays containing potassium bicarbonate or sulfur.
Botrytis (Bud Rot): Botrytis cinerea is a fungal pathogen that thrives in cool, damp conditions, often affecting dense cannabis buds. Infected buds develop a grayish mold and emit a musty odor. Proper humidity control, adequate airflow, and diligent pruning of affected plant parts can help prevent bud rot. In severe cases, affected buds should be promptly removed to prevent further spread.
Root Rot: Overwatering and poorly drained soil create ideal conditions for root rot pathogens, such as Pythium and Fusarium. Affected plants exhibit wilting, yellowing leaves, and stunted growth. To prevent root rot, ensure proper drainage and avoid overwatering. Additionally, using sterilized growing mediums and maintaining a balanced watering schedule can help safeguard against this disease.
Leaf Septoria: Leaf septoria is a fungal disease characterized by brown or yellow spots on cannabis leaves, often surrounded by a yellow halo. It spreads rapidly in humid conditions and can defoliate plants if left unchecked. Prevention involves removing infected leaves, improving air circulation, and applying fungicidal treatments containing copper or sulfur.
Prevention and Treatment
Cultural Practices: Maintaining a clean and sanitized growing environment, proper plant spacing, and adequate ventilation are essential preventive measures against pests and diseases.
Integrated Pest Management (IPM): Implementing a holistic approach that combines biological controls, such as predatory insects, with cultural and chemical control methods can effectively manage pest populations while minimizing environmental impact.
Regular Monitoring: Routinely inspecting plants for signs of pests or diseases allows growers to detect problems early and take prompt action before they escalate.
Organic Remedies: Many growers prefer using organic treatments, such as neem oil, insecticidal soaps, and beneficial insects, to control pests and diseases while minimizing chemical exposure.
In conclusion, proactive prevention and early intervention are key to managing common pests and diseases in cannabis plants. By implementing a combination of cultural practices, integrated pest management strategies, and organic remedies, growers can safeguard their crops and ensure a successful harvest. Continuous vigilance and adaptation to changing conditions are essential for maintaining healthy and thriving cannabis plants.
Congratulations, you are about to begin your home gardening adventure. There are dozens of considerations to designing a custom grow room, from lighting to location to security, but don’t let that intimidate you. The ILGM family has your back with decades of growing experience in all sorts of garden spaces to help guide you through the process.
If you’re reading this, you’ve likely been looking at the different areas of your house and wondered, how do I convert this into a cannabis grow room?
This article will provide all the information needed to build an indoor cannabis grow room. Regardless of the available size, budget, or location, we’ve got you covered. Growing your own cannabis offers the rewards of saved costs and premium products if done correctly. ILGM wants you to succeed and to have fun doing it, which is why this article exists. Let’s get started!
Growing cannabis in a small space
Grow room designs exist for all sorts of footprints. How much space do you need? The best way to choose the ideal size is to determine how many plants you wish to grow. ILGM has hundreds of quality strains; unfortunately, we don’t have enough space to grow them all at once. You can find how many plants fit in different footprints by reading our article: how many plants can you grow in a grow tent?
Check above how many plants can fit in a room size you are using.
Let’s say you want to grow a couple of small plants discreetly in an out-of-the-way location or windowsill in your home. Perfect; check out our article on cannabis micro-growing that will walk you through the considerations and steps to growing weed in a small space.
This article, however, highlights grow room designs for converting a larger space into a marijuana grow room.
Choosing the perfect room
Some growers can choose which room is best for them instead of making the only available option work for them. How do you decide? Well, outdoor growers have a saying – work with nature, don’t fight it. If your designs fit naturally into one room instead of another, choose the path of less resistance.
Cannabis plants grow best in the right environment, and temperature is one of those important variables. For example, if you’re deciding between a room with exterior, southwest-facing walls or one without exterior-facing walls, choose the second. It is much easier to keep the room in the middle of the house cooler than one that gets the afternoon sun.
The best cannabis grow room plans will utilize a room that growers aren’t afraid to do a little customizing in. Growing cannabis can be messy, although we preach cleanliness. The fact is, there will be soil spilled and water splashed onto the floor.
Rooms with concrete floors are ideal for cleanliness, but most people don’t have concrete floors in the house, only in the garage. You can sweep wood floors, but they can also absorb and retain moisture from spills. Rooms with carpeting can harbor pests and pathogens. Grow tents and drip trays can help mitigate these problems indoors.
Aside from the size, flooring, and location, there are still many things to consider when building a grow room; for instance,
Normal temperature fluctuations in the room (interior vs. exterior walls / north facing vs. south facing)
Average humidity in the room
Do windows need coverings to block light from escaping?
How many electrical outlets are there, where are they located?
Where will you exhaust the air?
Is it accessible to strangers, kids, or pets?
It is advised to have your vision for the grow room design and grow system worked out in your head before beginning construction. How to set up a grow room can be different for different growing styles. Hydroponic growers will need a water source in the room or very close to the room due to the requirements of that growing style.
Soil growers can walk down the hall to fetch water every few days without much inconvenience. Accounting for these small details will help you pick the right room to use. Below, we’ve highlighted the top three places to build a cannabis grow space in a house.
Attic grow room
This is one of the most underused spaces in the entire house. Attics are tucked above the main living areas, which adds discreteness to their potential as a marijuana grow room. Growers can customize this space to suit their needs, and ventilating the used air is as simple as connecting the fan to an existing vent.
Controlling temperatures can be challenging, and if you live in areas with annual snowfall, the bare patch on your roof might give your grow operation away. We go in-depth on the best ways to convert an attic into a cannabis grow room in our article – Attic Grow Room Tips.
Basement grow room
Whether you have an open floorplan or the basement is divided into different rooms, being below ground has advantages and disadvantages. This is another commonly underutilized area of the house that, with a little bit of preparation, can be turned into an excellent marijuana grow room.
The floors are typically concrete, there aren’t many large windows for light to leak from, and basements are a relatively secure area of the home. Extra equipment, e.g., dehumidifiers, may be needed to combat basement moisture, but everything is manageable. You can learn all you need to know about basement grow room plans in our article – Basement grow room tips.
Garage grow room
Another area of the home that, with a little customization, can make an excellent cannabis growing space. Smells, messes, and intense lighting are removed from the main living area, reducing a grower’s stress levels when company visits. Garages are also secured by locking doors, which can be ideal for growers with curious children.
Uninsulated garages will require work to mitigate temperature swings, humidity, and pests; however, they usually have adequate electrical outlets. Breaker boxes are commonly in garages, making installing a new outlet easier if needed. You can find the full list of pros and cons of growing marijuana in a garage in our article – Garage Grow Room Tips.
Equipment needed to build your grow room
For growers who like to make lists of materials and tools, the equipment needed to build a grow room can be divided into two sections: materials for construction and materials for growing. Obviously, you should purchase the materials for constructing your grow room first. However, remember that they both are coming from the same budget. It helps to have the big picture in mind.
If you are converting an existing room inside the house, most of the construction is already finished. My number one suggestion would be to buy a room-sized tent (8ft x 8ft [244cm x 244cm] or 10ft x 12ft [305cm x 366cm] ) or two large tents (4ft x 8ft [122cm x 244cm] ) for growers who want to run a perpetual garden. The large grow tent solution offers a drip tray for spills, reflective walls, and a frame to hang lights and other equipment.
If converting an open room, growers will need
a stud finder to locate ceiling joists to hang lights
white paint or mylar to increase the reflectivity of the walls
floor covering like tarps, linoleum pieces, or large drip containers that hold several pots
blackout curtains and velcro if the room has windows
Materials you might use to create your grow room.
Depending on the location and how well the walls are insulated, a few more items may be important. Items for controlling the environment, including
dehumidifier
humidifier
portable Air Conditioning
portable heater
circulating fans
Digital renditions of the products described above
To complete the picture, we’ve created an article for cost-conscious consumers titled – How to set up a low-budget grow room. In that article, you will find advice on lighting options, carbon filters, extraction fans, and many smaller accessory items. It also provides important factors for any grow space, such as being lightproof and airtight. But for those who have considered these things and are ready to move on, let’s get started with our design.
Make a grow room design
We shared a link earlier for determining the size footprint needed for the amount of plants that we want to grow. But how much light do we need to cover that space? That answer is in our grow light distance guide. Depending on the number of plants to be grown, you may not need the entire open space.
Gardeners who intend to grow only a few plants may benefit by planning their grow space in one of the corners. A corner placement allows more light to reflect from the walls back onto the plants compared to a few plants placed in the center of the room. You’ll want to access the plants from all sides, so add space for pathways around your plants. If space is tight, you may want to read our article about automatic watering systems for growing marijuana.
An overlooked aspect of grow room design involves electricity. Sharing the electrical load from grow equipment. Items like lighting, air conditioners, heaters, and dehumidifiers can require significant wattage from wall outlets. If a room has multiple outlets, design your plans to have these devices spread out. Consider which devices may be in use at which time. For example, although they both draw significant electricity, your air conditioning and heater are unlikely to run simultaneously. For more information about electricity in a grow room, check out our article – Electrical safety guide for growing marijuana indoors.
How to build your grow room
We’ve selected our room – three walls on the house’s interior and one exterior wall facing the front of the house. All the walls are properly insulated, so there is no need to make major corrections to the room. The full footprint of the room will be used for growing cannabis. Our first move will be to increase the reflectivity of the walls (and thus the efficiency of our light).
This can be done by painting them flat white or covering them with mylar. I prefer using the white paint option for a few specific reasons. The paint cost is lower than the cost to cover the same area using mylar or Panda film. You only need paint, a roller, a tray, some tape, and a tarp. You can also buy white paint with anti-fungal properties blended in; this is recommended.
An example of Panda film, anti-fungal white paint and a mylar sheet.
Mylar and Panda film doesn’t cling to the wall surface; therefore, there are pockets of trapped air between the film and the wall. When there is an extreme temperature differential between the outside and inside of the wall, microclimates and condensation in those small pockets can lead to mold growth. This material is better utilized in smaller areas like micro grows.
Step 1: Wall preparation
Total Time Needed: 1 hour 30 minutes
It’s important to conceal your grow by covering any windows using blackout curtains and velcro. Light leaks and odors are the two most common signals that someone is growing marijuana.
Black curtains that are always closed may raise the suspicion of nosy neighbors. Instead, use blinds or a decorative curtain between the blackout curtain and the glass. This way, when people are looking at the window from outside, it looks just like all of the other windows in the house.
This relatively quick procedure can take up to ten minutes per window. You will need your special curtains, 1.5in (3.81cm) velcro, measuring tape, and scissors.
While the total time takes about 90 minutes in labor, it also needs to dry overnight.
01. Tape off any trim around doors, windows, and baseboards (20 minutes)
02. Place drop cloths on the floor in the area you are painting to protect the carpet or hardwood floor (5 minutes)
03. Stir your paint, pour it into a paint tray, and get your roller fully saturated (5 minutes)
04. Paint all four walls; the ceiling is usually already off-white and doesn’t need a fresh coat (50 minutes)
05. Allow the paint to dry overnight (ensure proper ventilation and air movement, open the window)
06. Remove tape from the trim, window, baseboards, and door (10 minutes)
Step 2: Window(s)
Total Time Needed: 20 minutes
Measuring and hanging your lights when the room is empty is typically easiest. Looking at your grow room design plan, you already know where the lights will be hung. In this design plan, we are hanging two lights spaced at an equal distance from the walls and each other in the center of the room. We’ve calculated the light dimensions and distances; now, we need to drill the holes.
We will need a ladder, a stud finder, a tape measurer, and a pencil to place our marks. To hang the light, we’ll need a drill, eye-bolts or J-bolts, and the chain or yo-yos that will attach our lights to these anchors in the ceiling. For a visual tutorial of these steps, visit our article about hanging grow lights.
01. Measure the size of the frame around the outside of the window (2 minutes)
02. Cut velcro into four pieces, top, bottom, left, and right (3 minutes)
03. Apply one side of the velcro around the window frame and the other side to the blackout curtain (5 minutes)
04. Connect the pieces and ensure there are no creases or gaps that can let light escape (3 minutes)
05. Turn off all lights in the room for five minutes and then check the velcro area for any leaks (7 minutes)
Step 3: Hang the light(s)
Total Time Needed: 30 minutes
01. Locate the joists in the ceiling in the rough position you wish to hang your light(s) using a ladder, stud finder, and pencil (5 minutes)
02. Lay your lights on the floor in the intended position, aligned with the newly found joists (2 minutes)
03. Stand back and ask – are the lights still centered over the intended garden area? (1 minute)
04. Measure the distance between the attachment points on the light fixture (2 minutes)
05. Mark that distance on the ceiling, in line with the joists that the light will hang from (5 minutes)
06. Use a drill bit with a slightly smaller diameter than the eye-bolt or J-bolt that will be used as an anchor. Drill a pilot hole through the drywall and into the stud for at least 1/2 the length of the anchor (5 minutes)
07. Insert the eye-bolt or J-bolt and tighten. Use a screwdriver or long instrument to place through the bolt for additional torque while tightening (5 minutes)
08. Use a tape measurer or count the threads to ensure both attachment points are equal distance from the ceiling (2 minutes)
09. Attach yo-yos to the anchors, extend them to the floor, and connect the lights (2 minutes)
10. Raise the lights to the desired position to verify accuracy, then raise them to the ceiling to get them out of the way for now (1 minute)
Want to read more about how to hang your grow lights in your grow room? Please take a look at our article about how to hang your grow lights here.
Adding ventilation to your grow room
With the lights hung but out of the way, it is time to construct the ventilation for the room. The window in this room faces the street, so that is not an ideal place to vent the air. If your space poses a similar problem, there are a few other options for venting.
The first option would be to seal the room and use a charcoal filter to scrub the air. A downside would be the need for supplemental CO2, which comes with added cost and equipment.
Example of an charcoal filter/exhaust fan combo system.
The second option is to cut a 6-inch (15.24cm) vent hole in the ceiling and exhaust the scrubbed air into the attic or out of a roof vent. In any scenario, the exhaust fan should exchange the air once every 1-3 minutes. To calculate the correct fan size for your room, calculate the room’s cubic footage / cubic meter (L x W x H) and select a fan with the appropriate cubic feet/meter per minute (CFM / m3/min) rating.
Exchanging and exhausting the air every 1-3 minutes creates a negative air pressure in the room, which will passively bring in fresh air and CO2 through the cracks in the room door. Long runs of ducting or ducting with numerous bends will decrease the stated CFM, so buy a fan with more power than you think you need.
For this design, we are going with the option of venting out of a roof vent. For this task, we will need our stud finder, tape measurer, bow compass, a jig saw, 6-inch (15.24cm) aluminum duct connector, ducting, worm gear duct clamps, J-bolts, string, carbon filter, and an exhaust fan.
Step 4: Room ventilation
Total Time Needed: 1 hour
01. Use the stud finder to find a good place in the ceiling between two joists to make a 6-inch (15.24cm) hole and mark it with a pencil and bow compass (8 minutes)
02. Cut the ceiling hole using the jigsaw (use safety glasses for protection) and insert the 6-inch (15.24cm) aluminum duct connector (10 minutes)
03. Use the stud finder to find a joist between your lights for mounting the carbon filter and fan (2 minutes)
04. Drill the pilot holes and insert your J-bolts (5 minutes)
05. Hang the carbon filter and fan. Smelly grow room air will be sucked through the carbon filter and exhausted through the ducting into the attic (5 minutes)
06. Map the route from the fan exhaust port to the hole in the ceiling. Locate the ceiling joists along that route and place a J-bolt every 3ft (91.5cm). (5 minutes)
07. Use string to attach the ducting to the J-bolts in the ceiling along the route running between the output end of the fan to the 6-inch(15.24cm) aluminum duct connector in the ceiling. (10 minutes)
08. (Bonus) Go into the attic and attach ducting to the 6-inch (15.24cm) aluminum duct connector popping up through the drywall. Attach this ducting to a roof vent, and now all of the cleaned air is released into the atmosphere for further dissipation (15 minutes)
Setting up fans
Moving air within the grow space is also essential to grow room design. Air movement is crucial to reduce micro-climates within the canopy, areas of stale moist air in the corners, and to strengthen branches so that they can support heavier buds. One of the well-known reasons to move air around the grow space is to reduce the opportunities for powdery mildew (PM) to land and grow on your plants.
Marijuana plants are susceptible to powdery mildew
Place circulating fans on small stands, mounted to the walls or on the floor. At a minimum, you’ll want one fan moving air at the canopy level and another fan moving air below the canopy.
If you have a large room, fans may need to be placed on both sides of the room to ensure the middle section is getting good air movement. For a deeper understanding of the mechanics behind this and why good airflow is important, check out our article on Managing Airflow.
Step 5: Room circulation
Total Time Needed: 10 minutes
Remember to move air both above and below the canopy.
. Place a fan in the corner (fans mounted to walls will create vibrations and low-frequency noise. This is not ideal if you have neighbors on the other side of that wall) and turn it on to a normal speed. Walk away from it; how far does the air push? (4 minutes)
02. Set up a fan on the opposite side of the room and turn it on. Do the two create enough air movement in the center? (4 minutes)
03. If satisfied, set the fans to oscillating and ensure that their spread is enough to reach the corners of the room (2 minutes)
Controlling temperature and humidity in your grow room
An advantage of using a room inside a house is that the temperature will generally be in an acceptable zone. There may be the need for cooling in the summer and a little added warmth in the winter, but for the most part, temperatures are controlled already. Most houses, however, don’t have features built-in to control humidity.
Small dehumidifiers meant for tents, RVs, and closets will not impact the humidity levels in a large room full of transpiring cannabis plants. Growers will need to invest in the 30 or 50-pint dehumidifiers. Conversely, humidifiers should have a large enough reservoir that they don’t require filling every few hours. Learn more of these important details in our article – Create the best climate for marijuana grow room.
Step 6: Climate control
Total Time Needed: 10 minutes
Because these devices draw significant wattage from the wall, avoid using them on the same outlet as the grow light if possible.
01. Determine the square footage (square meter) of your room by multiplying the length x width (2 minutes)
02. Select a dehumidifier and/or humidifier that exceeds the square footage (square meter) of the room, preferably doubled (8 minutes)
Safety and fire prevention
The first rule in grow room safety is to have multiple smoke detectors in the garden space. I prefer one close to the lights and another near the canopy level.
A licensed professional should conduct any and ALL electrical work. Never “wing it” with electricity.
Do not place power strips or electrical connections on the ground where water can be spilled onto them; keep them elevated.
If you have to use extension cords, the shorter, the better; don’t leave large coils of extension cords around.
Keep any flammable materials away from the grow lights. This includes curtains, cords, and vegetation.
Always keep a fresh fire extinguisher at the entrance of the indoor grow room.
Use tape or twist-ties to secure loose cords to reduce tripping hazards.
Cleaning your grow room
“An ounce of prevention is worth a pound of cure,” goes the saying. It essentially means it is easier to prevent something than it is to repair the damage. This sentiment holds true to professional growers’ integrated pest management (IPM) strategies. Indoor grow rooms should always be free of loose soil, standing water, and leaf material. During a full grow cycle, there may be some stains on the floor or dirt accumulated in the corners. It is good IPM practice to clean the room between each cycle.
Cleaning products specific to cannabis grow rooms can be purchased, but the common cleaners are diluted bleach or cleaning vinegar. Wipe down everything from the walls to your soil containers to the shovel you use to scoop soil. Indoor grow rooms with a recent pest infestation should take extra measures, which may include not growing for up to a month to break the unwanted pests’ life cycle. You can learn more of these crop-saving tips in our article – How to Clean Your Grow Room.
Final thoughts on building a grow room
Designing a custom grow room for cannabis can be exciting. Now that you’ve read this article, you should know the many aspects to consider when designing a grow room and have the knowledge and confidence to make those choices.
If faced with a large blank canvas like an open room inside the house, I would use large grow tents instead of customizing the room. That is not always an option for growers due to availability or budget, and that is why we’ve created this article for designing an indoor grow room.
Remember, different areas of the house can call for different construction materials, tools, and techniques. Fortunately, we have specific articles for each of the main areas people grow. We also cover how to build a DIY grow tent if that is your preference. Regardless of where you decide to grow, for security purposes, cover the smell, block the light, and reduce mechanical noises that can give your grow away.
Designing the right grow room today can be the reason for future success. When a cannabis grow room is dialed in, all you need to do is grow like a pro. If you want to grow like a pro, all you need to do is download Roberts Grow Bible for free and get started on becoming a master grower.
Please let us know if you found this article or any other linked articles helpful in planning your grow room. Is there something we missed? We’d love to read your thoughts in the comment section. Have fun with your design plans, and happy gardening!
