Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Cabin Construction / Moisture
Author Message
Smawgunner
Member
# Posted: 26 Nov 2013 14:44
Reply 


Most small cabins I've been in seem to have a musty smell. Going forward with our build, I'm trying to prevent this at all cost. We're going to do spray foam, bat insulation in attic, vapor barrier etc. but is there something else you guys do when not at your cabin to avoid this? How do you keep air flow without letting in bugs, rain, critters? I envision buttoning up a nice warm cabin on a 20 degree day as I head back to civilization. Rapid temp changes are never good. Maybe I'll put a 200 lb bag of silica in the corner lol. J/k
Thoughts?

PA_Bound
Member
# Posted: 26 Nov 2013 15:29 - Edited by: PA_Bound
Reply 


IMHO... the secret is air exchange (ventilation). I am building my cabin with 5 vents in ceiling, near the peak, right below the ridge vent. A sixth vent will be installed under the roof of the porch, which faces what is typiclly the wind-ward direction. Each of these vents will be able to be closed with an insulated door to tighten the cabin up when I want to hold the heat, but will be open the remainder of the time to exchange the air (especially when I'm not there). Each vent will be screened with 1/8" mesh to keep the bugs out. That should allow the cabin to breath nicely when I'm not there. The porch vent should allow air to enter, the roof vents will let the air out.

I'm basing this plan on the experience I had with a hunting cabin. The cabin was tight, but during a particularly humid stretch one summer the humidity saturated the place, and without air exchange couldn't dry out. Add the summer heat, and when we opened the place up in late September the air was dank and mildew covered just about everything. We cleaned the place up, dried it with the woodstove and aired it out well, but it's never been quite the same. Even wth a tight cabin, sometimes there is just no way to keep the humidity out. Since then we taken to leaving the upper half of each window open and inch or so (protected by the roof overhang) and since haven't had the problem again.

MtnDon
Member
# Posted: 26 Nov 2013 15:37 - Edited by: MtnDon
Reply 


We've never been bothered by any smells like that. Our cabin is at 8800 feet, occupied pretty well full time most of May thru late August. The balance of the year it sees weekend use except for Dec thru April when it may only be used once a month if we snow shoe in. Never a bad small on arrival. We do not have moisture issues. Why? I'd like to think it is because we built the structure as well as we could taking care to seal likely points of air and water leakage. Well insulated, Well air sealed with sheetrock. We are NOT in a high humidity area, and that is a blessing I am sure, but it is not totally dry all year either.

Using a wood stove for heat probably helps some in cool and cold weather. But other than good construction techniques and materials we do not do anything special when leaving the cabin vacant for any period of time. Other than draining the plumbing in freezing weather, that is. And making certain that perishable foods are never left behind and that any food container that could freeze, split, leak and make a mess is not left behind inside the cabin.


Quoting: Smawgunner
We're going to do spray foam, bat insulation in attic, vapor barrier etc.


Be careful of combining the spray foam and a vapor barrier. Both in the same place = a bad idea. If you are going to spray foam walls I would use blown in cellulose in a ceiling over any kinds of batts.

Best place to read about air and vapor sealing and insulation is buildingscience.com. Insulation and air/vapor barrier design is climate specific. What has been done traditionally over the years is wrong for certain climates. The way people move around these days ideas get taken from "home up north" and if used down south = some very bad news, as one example.

rockies
Member
# Posted: 26 Nov 2013 18:06
Reply 


You might consider an air to air heat exchanger. They are normally installed on furnaces or for ventilation fans in kitchens and bathrooms to capture the heat from the outgoing stale air, but it could probably be set up by itself (with some vent pipes attached and running to each room) to run on a battery and a timer for a short period of time each day.

adakseabee
Member
# Posted: 26 Nov 2013 18:29
Reply 


At my cabin in central NYS we don't have extreme humidity issues, but nevertheless, summer weather is very often characterized by late afternoon and evening thunderstorms. I have enclosed soffits with screened vents and a continuous ridge vent. There is free air exchange from the soffit vents up through the loft to the ridge vent. As this cabin was built for fair weather use only (late spring, summer, early fall), I did not insulate it. In three summers of use, have not experienced any problems.

KinAlberta
Member
# Posted: 14 Sep 2020 13:25 - Edited by: KinAlberta
Reply 


Good articles below.

3 Types of Moisture Absorbers Explained | DoItYourself.com

https://www.doityourself.com/stry/3-types-of-moisture-absorbers-explained

Keeping Mold And Moisture Out of An Unheated Cabin | The Money Pit

https://www.moneypit.com/keeping-mold-and-moisture-out-unheated-cabin/

5 Ways To Make The Best Homemade Dehumidifier

https://byemould.com/2017/09/04/homemade-dehumidifier/

In our case I was surprised one fall about three years ago to find all the cabin’s interior walls frosted over. That means a lot more moisture than I thought likely can build up inside. The cabin is vinyl tile flooring and knotty pine board walls. The kitchen cupboard bodies however are that pressboard junk. (When i dragged a small bookcase outside during one cleanup I was shocked at how awful it stunk. Really putrid smelling! I figured its pressboard construction was absorbing moisture and then rotting.

So now I’m thinking that too much moisture getting into our kitchen cupboards off season when the cabin can be vacant for weeks or months at a stretch can’t be a good thing. (Cabin is lakefront, unheated, on blocks, no plumbing, climate is extremely dry in winter but spring and falls can be very rainy.)

Brettny
Member
# Posted: 15 Sep 2020 08:07
Reply 


Quoting: adakseabee
At my cabin in central NYS we don't have extreme humidity issues, but nevertheless, summer weather is very often characterized by late afternoon and evening thunderstorms. I have enclosed soffits with screened vents and a continuous ridge vent. There is free air exchange from the soffit vents up through the loft to the ridge vent. As this cabin was built for fair weather use only (late spring, summer, early fall), I did not insulate it. In three summers of use, have not experienced any problems.

With no insulation you wouldnt see this problem. Your interior temp closely mimics the outside temp so wouldnt get condensation.

Condensation happens when the items in your cabin are cold and warm humid air is allowed in. The hot hit hits a cold object and makes water droplets. Allowing for air exchange when your not there will help as the temp change shouldn't be so large.

Also non vented propane heaters put moisture in the building.

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.