Install Cabinets directly above Tongue & Groove?

caezaar

Our kitchen flooded and the plywood subfloor had to be removed.

All that remains is 2x8 fir tongue and groove boards resting on joists. We can see the dirt under the house through some gaps and knots big enough to put your fist through (old 1965 construction).

Our contractor is installing the cabinets above the tongue and groove with just a few slats around the edges.

To me this seems strange. No subfloor, no moisture barrier, and some gaps between the 2x8s big enough for a critter to move in under each cabinet.

Should we ignore this or insist that a subfloor (or something like a moisture barrier?) be installed between the tongue and groove and the cabinets?

Thanks.

Our contractor is 90% done installing our kitchen base cabinets directly over tongue and groove (using a few strips of plywood around the edges only). We can see the dirt under the house between the T & G boards and there are numerous gaps and 2" holes in the boards where knots came out), so I'm concerned that there should be some type of sub floor and/or moisture barrier.

Is it worth having him tear them out and put in a sub floor?

2 threads on same issue merged

nap

what is he attaching the T&G to if there is no subfloor under only the cabinets?

If there is a subfloor in the rest of the room, that would mean the T&G is up off the joists the thickness of the subfloor.

based on what you have, yes, you need a subfloor. What you have now will allow insects and animals to come into your cabinets.

Just Bill

definitely needs new subfloor, and that crawl space should be covered with plastic to keep down moisture.

caezaar

Thanks Nap. He cut strips of plywood (perhaps 5" wide) and put these under most of the edges of each cabinet. Some all four edges and some just three. Thus the cabinets are above the T&G by the thickness of the plywood.

JCarsten

If you have a crawl space under the kitchen, you definitely need to have the contractor fill the "gaps" under the cabinets. You most likely aren't going to get him to remove the cabinets and reinstall, but rather fill from below.

caezaar

Thanks JCarsten. Are you thinking that expandable foam or something similar?

JCarsten

That's what I would use.
If you are seeing "dirt" in your crawl space, you might want to look into your local building code (or ask your local inspector) about a vapor barrier. States most likely vary on code, but in MN we are required to put a vapor barrier over ground cover in a crawl space.

caezaar

OK Contractor argued that:

• The T&G is enough of a subfloor
• If house had any history or possibility of moisture or if T&G was laid diagonal with gaps then, yes, a moisture seal and subfloor would be required.
• that the dry dusty sandy area under the house has little/no moisture
• the prior chipboard subfloor in the house has been dry for 40 years
• that they filled any missing knot holes and the tongue seals are tight
• They been installing cabinets for 7 years and install on plywood strips over T&G constantly
• That they could 10 other contractors who would argue that it's fine (given the above)

They were already planning to tile under the fridge and dishwasher.

Given all that, and the work they've done so far seems to be of good quality, and that they are doing this for a very fair price, it seemed compelling enough to not stop everything, tear out the cabinets, cancel granite installers, tile installers etc, and let them continue.

nap

a subfloor by definition is a layer laid below the final flooring surface. If this is the only layer of flooring, there just isn't any subfloor, or main flooring


Huh? Laying it diagonally somehow makes it seal better or worse?


irrelevant if code requires the crawlspace is required to have a vapor barrier

good but that still does not mean it is legal or proper

good, at least they filled the holes. How tight are the tongue and groove joints when that dry air under the floor causes the boards to shrink?

Wow, 7 whole years. As an electrician, I had a 5 year apprenticeship and there was still a lot of things I didn't know. Now, after another 9 years, there is still a lot I don't know. 7 years ain't squat.


I would ask for names

the thing the guy fails to mention is that a subfloor is usually under another layer of flooring. As such, the knotholes and a not quite as tight fit isn't as important as it is when the subfloor is the only floor. The fact it is the only floor, the integrity of that floor is much more important.



you have granite going in and this guy cheap shots a little bit of floor boards? He should have at least tossed down plywood to cover the area rather than shimming the cabinets like he has.

I would suggest speaking directly with your local building department and getting their take on the situation. If it passes code, the it is what it is and you demanding any additional work will come as additional cost. If it doesn't pass muster, then the guy can fix the thing.

Either way, you can have some peace of mind knowing what the building department requires.

Gary in WA

"Our kitchen flooded and the plywood subfloor had to be removed. " -------- (underlayment)

"All that remains is 2x8 fir tongue and groove boards resting on joists." -------- (sub-floor)

http://bct.nrc.umass.edu/index.php/p...ient-flooring/

http://www.apawood.org/pablog/index....-Floor-Systems

The 1x's ALWAYS get a underlayment between it and finish cabinets: Page #150-152: http://books.google.com/books?id=bwt...page&q&f=false

At the very least, install builder's paper...... If the crawl space is vented, expect some warpage in the cabinet drawers and doors next Winter. (And bugs, spiders, mites in the house).

Usually, finish floor material is installed on the underlayment right next to the cabinets, unless tile.

Ask your Fire Marshal or B.D. as it has to be fire-stopped (no gaps) between floor and crawlspace. Page 4- fire-blocking: http://www.codecheck.com/cc/images/CC5thEdSample.pdf

Be safe, Gary

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Ron6519

Putting cabinets over that sort base is idiotic. It subjects a finished wood product to excessive moisture. Any competent contractor would have discussed the crawlspace issue long before he started the job. Vapor barriers, insulation and a plywood layer should have been discussed, based on your location.
Ron

Gary in WA

Could a moderator join these? Install Cabinets directly above Tongue & Groove?

Be safe, Gary

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nap

I thought I had posted to this question before but when I looked at the other thread, I wasn't there.

Gary in WA

Been there, done that. Feel older than before..........lol

Be safe, Gary

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