post and pier addition question
I am planning a 12 by 15 foot bedroom addition onto our existing home. one builder is suggesting a 6×6 post and pier foundation for the addition as a reasonable way to save money on the construction costs. We live in wisconsin so weather is an issue.
I basically like the idea in that we have plenty of basement under the rest of the house and would love to avoid digging up and putting in and connecting a new basement or crawl space. The only utility that we would need in the addition is electicity and heating vent which is easily and convienently located.
So i guess the main question is on the stability and longevity of a post and pier foundation for a small addition.
Marc
Replies
Whole building are built that same way in earthquake areas. Bridges are built that way.
The important thing to remember is the quality of the base on which the building rests. It needs to be sufficient to support the load and deep enough that it will not be effected by the freeze and thaw cycles.
Done right, I wouldn't have any concerns about the longevity of a pier foundation. I would be concerned about insulation, however. Floors are difficult to insulate well, and a bedroom with a cold floor does not seem like a great feature. How does he propose to insulate it?
Ditto. I've done a few small "sun-rooms" like that, (personally, I prefer a frost wall and crawl space to piers) but..... Insulation and also a way to cover the bottom of the joists depending on ground clearance always a concern. My own house has a 2' cantilever w/ fiberglass batts, covered on the bottom w/ 1/2" cdx , probly 3 ft off the ground, and when you walk across hw floor when it's cold out there's anobvious line where the overhang starts.Sorry I don't have a great solution, but if I were to do it again, I'd do radiant anywhere I wasn't over a full basement. My boiler is down cellar, and it never seems to get really cold down there. Chilly when temps get below 20 or so, but never fridgid like under an open floor.
bing
Why not a full footing/foundation combo?
The last thing i'd cheap out on would be the foundation.
No reason at all not to do it. Plumbing is often a pain with piers, but as you have said not in this case. Insulate the full depth of you floor joists and run an inch of foam on the underside before you sheath to stop thermal bridging. It will be cool to the touch, but a lot warmer than the walls if it comes to that.