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Seeking help on what I think might be a bad contractor job

Posted by cakequeen (My Page) on
Wed, Aug 10, 11 at 23:44

HI, we just had our sub-basement (half above/half below grade) tricked out for a tv room. I have questions about two things: above grade insulation and below grade.

I see that the contractor put some insulation against the exterior concrete foundation wall. I've never seen this product before. It looks to have between 1/4" thickness at most and seems to be a greyish foam-like material I see in some packing embedded onto a rather rigid plastic mesh. It was shoved up against the exterior concrete wall with no gravel backfill. I don't know if there was waterproofing on the concrete wall - not sure how to recognize it. There is no black tar-y material that I can see. The mesh material is flimsy and isn't attached to the concrete in any way. It doesn't even touch it in some places because is more like a rigid netting. After it was pressed close to the foundation wall it was backfilled with regular garden soil. No gravel.

Does anyone know what kind of material that was applied?
How do I recognize waterproofing on the vertical walls below grade?
Do I need to dig this back up and put in other insulation and gravel?
The contractor is long gone, so contacting him is no use. He won't answer emails or phone calls. I'd like to fix the problem myself if I can.

The other question I have is that we had him put some rigid insulation against the concrete foundation wall on the interior of the basement. He then used regular fiberglass insulation in the stud walls (dn't know the rating), with a layer of sheetrock. The room is cold.
Should there have been some other type of insulation in this instance? Would foil backed insulation have been more appropriate for this situation?

I am worried about having to redo the entire thing.


Follow-Up Postings:

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RE: Seeking help on what I think might be a bad contractor job

Post some pictures of the exterior and interior foundation walls and let us know what your climate zone is, or approximate geographic location.

Thermal insulation doesn't warm or cool a space; it simply slows down the rate of heat transfer.


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RE: Seeking help on what I think might be a bad contractor job

Its difficult to show as the interior is now covered w/ sheetrock w/ no foundation walls exposed. The exterior area has been backfilled w/ soil and is not exposed. I can try to dig the soil away from the foundation some. I live in San Francisco where the weather is relatively mild to cool, lots of rain in the winter.


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RE: Seeking help on what I think might be a bad contractor job

I think we can safely say that whatever is on the exterior is not insulation. As described, the inside insulation sounds correctly layered and installed. You don't mention what insulation, if any, there is on the rim, that is, the board onto which the joists connect.

As mentioned earlier, insulation by itself won't keep your basement warm. It needs a heat source in winter.


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RE: Seeking help on what I think might be a bad contractor job

HI, I dont know what is on the rim, unfortunately.

There is a modest amount of heat coming from a single vent near the ceiling. It is inadequate to heat the room. I had hoped that the wall and foundation insulation would be better at keeping the heat that does come into the room.

I'll try to dig up what I can at the foundation. It goes down about 4 feet. What kind of waterproofing do you recommend? And what kind of rigid do you recommend? I see some corning drain-mat in another post. Should I add that and backfill w/ gravel?

I appreciate the helpful comments. Thanks a bunch. This is not a good situation to be in.


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RE: Seeking help on what I think might be a bad contractor job

Insulation scope sounds proper and is more than code really requires. Using that as a leveling tool against his work, it might be entirely likely that he did the job better than code calls for.

Most of the discomfort issues in basements are because of cold floors and air leakage. You will get copious amounts of air leakage at the ribbon/band board and the sill to poured wall connection.

Gravel back-fill against the foundation wall is not normal.

Gravel around the weeping tile, yes.


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RE: Seeking help on what I think might be a bad contractor job

Granular backfill--which includes sand--around the foundation aids in drainage.

Asphalt cutback is next to useless. So don't worry if you don't see it.

Again, pics will help posters. Open a Photobucket or other free photosharing/storage account.

Here is a link that might be useful: What Factors Make a Better Basement


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