How do you Insulate a 3 season cottage?
We want to insulate a 3 season cottage to keep it cooler in the summer and warmer in the spring and fall. We are putting a metal roof on and insulating on top of the old one. Is it better to insulate the rest of the cottage from inside or the outside? And what kind of insulation is better? The inside of the cottage right now has no finished walls
From what you describe, I would do it from the inside. If the interior is bare stud framing and it has siding on the outside (and you are really just looking for a bit more comfort in the spring and fall) then I would treat it as a normal stud-framed house wall that needs insulation, and an air and vapour barrier. This wouldn’t be my recommendation if you were looking for a fully winterized cottage that would act as a full-time home, in that case we would propose a much better performance target. But for what you describe and if you aren’t looking at it for long term resale value as a home then I myself would keep it simple.
I would have the wiring inspected and updated if necessary, add batt insulation (Rockwool or fiberglass) then a poly vapour barrier, maybe strapping, then drywall. Strapping isn’t absolutely necessary and it will eat up a bit more space. It can help prevent drywall from cracking, but if you’ve been staring at a stud wall then minor cracks in drywall may not offend you if they show up. Cottages usually shift a bit more than houses so a little cracking is not unusual. And am I correct in assuming it’s a 2x4 wall?
If you wanted a bit more comfort and savings you could add a rigid board insulation to the interior as well, but that will eat up a bit of space so that’s really up to you. If I’m misunderstanding the existing structure please feel free to correct me and we can come up with other solutions for you.
The existing structure is probably 80 years old so it looks like almost a wood cabin. I believe it is cedar that has been stained and the ceikling is also exposed. We do not want to cover the ceiling that is why we are insulating the roof from the outside. This will always be a 3 season max cottage. It has been in the family since the beginning and we are not worrying about resale value. We are putting a wood burning stove in and like I said just looking for a little more cooler in summer and warmer in early spring and late fall. The structure is 2 x 4 studs. We just had bthe whole place rewired to code
First of all I'm glad to hear that you've got the wiring re-done, that is a serious safety concern with such an old building.
Most 'building science' issues like the risk of moisture movement in winter and the ensusing risks don't really apply to a 3 season cottage, that doesn't have air conditioning nor would I say do the performance standards that we like to target, so as mentioned above I would but batts between the studs, a vapour barrier and then some drywall or wood as you prefer.
You didn't mention much about the floor, so I'll go ahead and make a few assumptions and suggestions - I imagine the floor isn't insulated, and if the cottage is up on piers and open underneath like most of the ones I'ves seen, then you may want to do that as well at some point. An easy way to do that is with spray foam, and we specifically recommend looking for a brand that has switched ot safer blowing agents. At this point we know of two - Demilec and Elastochem, but will likely be more following suit in the near future, so for you and anyone else reading this, ask a spray foam installer if they have switched to the new HFO blowing agents, here is a link that explains more. And if you do insulate from underneath and are concerned about rodents infesting it, you could staple up some diamond lath metal mesh for prevention. Good luck Terry!
Our three seaon 1,500 square foot cottage was built in 1978.
There is a full unfinished basement.
Please inform me re: winterizing it to a 4 season cottage.
We have capacity for a gas furnace.
A contractor said we did not need to insulate the basement???
I am a first-time visitor. I do not know how to ask a question.