Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 8/28/2016

Is it worth to put a foundation on a 3 season room

I have a 3 season family room on piers. Should I put it on a foundation?

Do you have the same question? Follow this Question

1 Answer


The time to decide the foundation type would be before it is built. If you are in an area with significant frost penetration or expansive soils, shallow piers will likely move up and down over the seasons (commonly staying a bit higher each cycle), so in that case or if it has a lot of glass, a normal house type foundation (full foundation or full-depth piers supporting a strip sill foundation NOT supported on ground would be recommended - except that it would have to go the full depth below deepest frost line, not the reduced depth commonly allowed for foundations that are always heated.

Generally - this is true for any structure connected to the rest of the house (other than by intentionally moveable flexible water and insect barriers), so it does not tear the interface between it and the house or try to lift the house at that point.

A 3-season room NOT structurally connected to the house or roof can be built on a shallower foundation, though expecting some cracking of walls and any tightly-mounted windows or glass-wall construction - as is normally the case.

Whether it is worth doing now - depends on what type of foundations you have now compared to what it should have, amount of glass at risk, whether it has performed satisfactorily till now, and whether the lack of deep foundations is going to cause a problem at resale inspection time. Certainly the cost of putting in normal foundations after the fact is likely to be on the order of around half or more the value of the room, so most people would not do it unless forced to - plus if it has a lot of glass liek a Florida room or sunroom, unless the glass was removed during the work and then reinstalled (which would likely involve a cost for adjusting glass framing too), putting in the foundation now might cause as much damage as you would expect from heaving.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy