R405 foundation drainage/crawl speace

[Bootleg]

If or when a perimeter footing drain would be required for a SFR with a crawl space?

Is a crawl space a useable space located below grade?

A house with a crawl space is not required to have foundation drainage?

 

[steveray]

I don't believe so for a crawlspace....an unfinished basement, may be "useable" and may become "habitable" so yes...Crawlspaces are not generally "useable" in my opinion!

 

[fatboy]

From the 2009 IRC,

R405.1 Concrete or masonry foundations.

Drains shall be provided around all concrete or masonry foundations that retain earth and enclose habitable or usable spaces located below grade.

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I agreee with steveray, yes to any type of basement, no to crawlspaces.

 

[JBI]

My mother-in-law has a crawl space under her SFR. It contains her HVAC system, pressure tank and water filter. The filters require periodic replacement, sound 'useable'?

 

[Daddy-0-]

If the crawl grade is lower than the outside finished grade we require waterproofing the foundation not damp proofing. One way to waterproof is to coat the foundation wall with portland cement and tar or equivalent AND add a foundation drain and sometimes an interior drain as well. If the crawl grade is higher than the outside grade no drain is needed. Waterproofing is always required with a basement here. NOTE...2006 code here still.

 

[Yankee]

No. I believe usable means basement, whether finished or unfinished.

 

[Mark K]

If the crawl space is lower than the adjacent grade waterproofing the foundation will be a waste of effort. The water can still gounder the footing and the foundation without waterproofing will divert free flowing water. In this situation you want ventilation of the crawl space and drainage to allow any water to flow away. A sump under the house with a free flowing drain away from the house would probably be as effective as a perimeter drain.

 

[Mark K]

If we look at Section 1805.1.2 of the 2009 IBC we see that if the ground water table is lower than 6" below adjacent grade, the surface water readily drains away from the building site, or the level of the crawl space is at or above finish grade level then neither waterproofing or drainage is needed.

 

[Yankee]

If we look at Section 1805.1.2 of the 2009 IBC we see that if the ground water table is lower than 6" below adjacent grade, the surface water readily drains away from the building site, or the level of the crawl space is at or above finish grade level then neither waterproofing or drainage is needed.

I believe the question is in a SFD (IRC)

 

[peach]

equipment in a crawlspace put it in usable space.

It's not habitable space.

I have yet to see this kind of crawlspace without appropriate dampproofing/waterproofing/drain tiles installed.

 

[Yankee]

I can see perimeter drains or sump, I am not convinced about damp or waterproofing the exterior of the concrete walls. Unless the space is to be "finished", to what end would that be done?

 

[peach]

soil conditions (for one)... concrete (and blocks) wick water like crazy. Keep outside water outside away from the wood and the equipment in the crawl space. I'm not convinced (unless it's a really well ventilated or conditioned crawlspace) that at least damp proofing shouldn't be required.

 

[rogerpa]

R408.5 requires the drain.

 

[mtlogcabin]

Interesting thread and the timing is amazing. Local contractor built about 120 homes in his subdivision over the last 5 years is being sued for water in the crawl spaces by 6 home owners so far. He damp proofed the foundation walls and installed a drainage system. However he did not provide sump pumps and that information is in his closing documents. The water in the crawl space is caused by a high water table and coming up from below which historically never existed untill recently. I am in the process of making copies of 120 building permits and inspection reports. Maybe in 3 or 4 years I will have a local court opinion as to what a "usable space" is.

 

[peach]

The builder is in violation of his contract with the homeowners. How do you keep the joists healthy even with good ventilation or conditioning when there is standing water (which will turn to vapor at some point)? There's probably insulation, ductwork and possibly equipment in there. I hate crawl spaces, btw.

 

[texas transplant]

Oh Peach,

Crawlspaces in a perimeter footing system are a good, WHEN installed right with ventilation, drainage, sump pump when and if necessary. Its like any other system install it right and it lasts like it should, install it wrong and you have problems. I personally like crawlspace instead of pier and beam or slab on grade it allows changes and repairs that slab on grade doesn't and when installed correctly provides a longer life than pier and beam without as much movement.

 

[peach]

I prefer basements, thanks Tex. Crawlspaces are so frequently NOT installed correctly.

 

[fatboy]

Guess I'm glad I live in the Great American Desert, locally we don't have issues with high water tables. And seldom di we see crawlspaces anyway, because there isn't an issue with water tables,, builder almost always go with full basements.