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 1/26/2017

how much per sq ft to fill in in a 20 ft by 22 ft sunken room that is 6 inches deep using wood

Do you have the same question? Follow this Question

1 Answer


Depends of course on whether you are going to try to level the floor (so need custom trimming of the joists), also exactly what the dimension to be raised - because 2x6's with 3/4" sheathing would total 6-1/4" - plus the flooring thickness - so if that would be too high, each joist will have to be ripped or planed to less than its normal 5-1/2" width - adding probably a couple hundred $ labor to the cost.

I get (at my contrator account cost) about $720 materials using OSB sheathing, or about $1120 using 3/4 CDX plywood (my preference), so with contractor markup (if he provides them) probably about $800-2250 materials depending on which material you go with and whether his markup is low (10%) or very high (100%).

Labor probably about $25-50/hr for a carpenter or handyman - so say (including going and buying materials (18 - 20' 2x6 and 14-15 sheets sheathing, so definitely a have-them-deliver case - so about 5-10 manhours probably depending on ease of getting the materials into the room, amount of trimming needed, etc - so maybe $125-500 labor, depending on local labor rates and whether this is a true "business" or a one-many "enough to eat" handyman doing it with a low-paid helper (this is a 2-man job, at least for moving the materials in - unless you can help with that).

Therefore, total cost I estimate maybe $925 - $2750 total depending on factors above - lower range only for low cost contractor, $2000 range far more likely with an established contractor.

Note - assuming this is an on-grade slab you are going over, be sure to provide some ventilation for the subfloor areas (at least an open large central air vent at each end, minimum). I would put in minimum, for this size room, 2 vents at each end, and ventilation holes drilled (say 2-3") every 6 feet say through each joist - to provide some cross-ventilation through the joists to the vents. Of course, some active airflow through there would be MUCH better.

Also - for the extra $100 or so, I would go with treated timbers, because you have a chance of that subfloor area getting moist. If there is ANY chance of that area getting wet from flooding (up from slab or through foundation walls or such) I would require the sheathing be put down with screws rather than nails so pieces can be taken up if needed in the future - though would have to put thin strips of padding on top of the joists in that case if not gluing it down as one normally would, so it does not make a lot of noise. Putting padding on the joists (non-biodegradable type) is a good idea anyway because of the risk of the open space underneath becoming like a sounding board, especially if putting hard flooring over it instead of padding and carpet, where I would not worry about padding the joists.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy