Most people are familiar with insulation for their home, but they do not always consider insulating their shed. Insulating your shed with foam is a smart way to keep the contents of your shed safe from extreme temperatures and weather.
Why Use Foam for Insulation?
Very Effective Insulator
Closed-cell foams, such as polystyrene (EPS) and polyethylene, are fantastic insulators with high thermal resistance. Thermal resistance is calculated through a material’s R-value. A higher R-value means the material is better at resisting the flow of heat between two areas.
R-values are defined based on the thickness of the tested sample; layering two identical sheets of foam will provide double the thermal resistance.
Durable and Long-Lasting
Thanks to the structure of foam, it is one of the most durable and long-lasting materials on the market. In addition to the thermal qualities, closed-cell foams are resistant to moisture and water vapor, rot, mold, and mildew.
Easy to Apply in Any Condition
Compared to spray foam insulation, using sheets of foam requires less tools and involves less cleanup. Additionally, spray foams usually require certain air and surface conditions to be applied appropriately. Sheets of foam, on the other hand, do not have those restrictions and can be safely installed year-round.
Before You Begin
Before you dive into your insulation project, there are a few things you should take care of:
Inspect for Leaks and Cracks
The best insulation in the world will not do much if there are holes in your shed! Before insulating your shed with foam, it is a good idea to fix and seal windows, repair siding, and patch rooftop leaks.
Keep in mind that a wood or vinyl shed exterior has a lower R-value than closed-cell foam insulation, but it still contributes to the overall thermal resistance of the enclosed area.
Take Care of Other Renovations
If you plan on converting your shed into a small home or barn, you’re going to want to do more than add insulation and call it a day. Depending on the climate, you may want to add heating and air conditioning to ensure the comfort of your shed’s inhabitants throughout the year.
This is also a good time to take care of any other electrical upgrades. Extra lighting and electrical outlets can go a long way towards transforming a shed from a simple storage area to a cozy home or productive workspace.
Unless you have experience, it is best to hire an electrician to take care of any electrical renovations.
Insulating Your Shed With Foam
Rigid Polystyrene for Flat Walls and Ceilings
Much like insulating your home, the primary way to insulate your shed is to apply sheets of foam to the walls and ceiling.
Using an electric knife, sheets of polystyrene foam can be easily cut to specific sizes to cover your shed fully. The recommended method for affixing the insulation to the walls and ceiling is with a non-solvent spray adhesive, such as Camie 373.
Pliable Polyethylene for Everything Else!
If your shed has a curved roof, the rigidity of polystyrene may not be ideal for the job. Similar to polystyrene, polyethylene can be cut using an electric knife. It can also be adhered to the wall or ceiling using spray adhesive.
If your shed contains pipes, they can also be insulated to prevent energy loss. This can be accomplished by wrapping the pipe in polyethylene roll, and using spray adhesive, adhesive tape, or rope/twine to hold the foam in place.
6 thoughts on “Insulating a Shed with Foam”
Hi – you have some good info on this blog – thanks. Four questions about flexible insulation please (I need to patch up some gaps/holes in both my attic and my crawl space, and the manways are only about 2′ x 2′ – so I can’t use rigid polystyrene – it wouldn’t fit).
1) In terms of R-values (per inch), is there much difference between cross-linked polyethylene (2# density) and polyethylene (2.2# density)? I think they’re similar, but it’s not clear from your data sheets.
2) What about using neoprene as a flexible insulator, versus polyethylene? I think it’s more dense, so would weigh more – but how’s the R value compare to the materials in question 1)?
3) Regarding the lowest fire risk, which of the products from 1) or 2) would be best for attic/crawl space insulation?
4) Any thoughts about using high density (1.8#) polyurethane (upholstery foam) for insulation? It’s open cell, so I’m assuming not as good as the above options – but I’m curious about comparative R-values, flammability, etc.
Ok thanks again for your blog and regards.
1- Yes the foams are similar in terms of R-values. 2- Yes Neoprene-HQ can be used for insulation. However we do not have test data. 3- Neoprene-HQ is fire retardant. We do have Minicel LF200 that has a high fire retardant rating that could be used for that application. 4-Polyurethane foam is not suggested for this application.
I have left over styrofoam from delivered packages. Will the leftover styrofoam provide insulation if I apply it to the interior walls of my outdoor shed?
Please Contact Us for more information regarding your inquiry.
The metal roof of my shed is attached to 1×4 planks. The metal gets very hot in the Florida sun. Can I apply sheets of styrofoam to the 1×4 to block the heat or will it melt?
Based on the manufacturer testing for our Polystyrenefoam, its long term service temperature is 167 degrees, so it should not melt. That information can be found here.