ANSI---interior basement walls

[Zoe]

Basement Foundation Thickness​

Basement foundations include walls and a concrete slab that acts as the floor. Since the walls and supports hold up the structure rather than the weight sitting directly on the slab, the slab in a basement is usually just 4 inches thick. Contractors might opt for a 6-inch slab instead to reduce the risk of moisture wicking through the concrete in areas prone to flooding or drainage problems. Thicker slab foundations cost more but can help avoid expensive problems in the future.

Building code throughout the U.S. requires that basement walls be no fewer than 8 inches thick. Most basement walls consist of stacked cinder blocks, which are 8 inches thick. This thickness is suitable for walls that are 8 feet tall and have at least a foot protruding above the ground.

Many modern basements include full-height ceilings, which require 10-foot basement walls. The higher your walls, the thicker they need to be, so tall basement walls might need to be 10 to 12 inches thick.

8-9 inches should cover it on all exterior walls.

 

[Tom D]

Are they asking for all of the interior walls or just the walls that separate the finished area from the unfinished area. This is what mine looks like and I have never been questioned. Doesn't take long at all


View attachment 89375

wow, i have never done it your way once, and never a question either. the problem here is the tolerance level of the lender, and your tolerance level of the lender. but, if you want to be a sketch perfectionist, be one. long, long ago, you made the sketch with a magic marker, drew a rectangle, no basement shown either.

nice to see a different appraisal question. the politics here are a little on the too much of it side.

 

[Zoe]

If you have 8ft ceilings use 8-9 inches on outside measurements only because inside walls are likely 4.5-6 inches thick and built with wood.

Here is a reference.

How Thick Should a Foundation Be?

How thick a foundation should be depends on a few factors. Learn about minimum thicknesses for different foundation types and soils in this guide.

www.angi.com

Again the inside walls are included in the overall living area of the basement if you include outside walls. Same as above ground area on ground floor. Sometimes you have to measure inside walls in areas where you can't measure outside foundation walls from the interior. Like from N/S/E/W, you may have to get those measurements inside including inside wall thickness and add for outside wall thickness. Many 1.5 stories (+) are same way with ANSI on single family construction.

 

[Tom D]

the easiest way to measure any interior is get a laser gadget. forget the wall thickness if they want basement interior measurement.

 

[Zoe]

wow, i have never done it your way once, and never a question either. the problem here is the tolerance level of the lender, and your tolerance level of the lender. but, if you want to be a sketch perfectionist, be one. long, long ago, you made the sketch with a magic marker, drew a rectangle, no basement shown either.

nice to see a different appraisal question. the politics here are a little on the too much of it side.

It can get on an old man's nerves like me. Let's not bring politics in this one. LOL