Adding a basement

I'm planning to add a basement to my large 2-storey house -- the house currently has a concrete-block foundation. This is, obviously, not a DIY project, however I'd like to learn as much as I can about pouring concrete foundations, supporting the house while digging out the new basement, good drainage/waterproofing systems (it rains like a dog here in Seattle) -- so that I can deal intelligently with the contractor.

Any suggestions for information sources will be greatly appreciated. (Book titles, web sites, publications, tutorials, etc)

Larry

 

Id go down and check code first there for sure. I think that when you find out how small the basement will be you might not do it. To dig the new basement you have to set back in so far from the footing that is there now. That you dont have much room left.

ED

 

If you currently have no basement and just a rather shallow foundation, you will have to underpin the house to install a new basement under the house in place of the current foundation. The support of the house should be the responsibility of the contractor for legal and common sense reasons.

If you are doing this, many contractors prefer to work with concrete block because of the ease of construction when handling materials and building materialsup to the house. It is difficult to pour concrete inside forms that go up to the bottom of the house structure. The strength of the walls can be the same for either material.

If you are considering adding foundation walls inside your current foundation, you will gain little, since the walls would be inset considerably.

The main point in waterproofing is the insrallation of drain tile, sump and a sump pump. This eliminates the water from around the footings and the under the floor slab. The surface coatings used are secondary if you control the water. Control of the surface water (rain) with gutters and long downspouts is critical, obvious and inexpensive.

Dick