Sonia

Hi Sonia,

A walkout basement needs to have concrete walls for structural strength when the walls are less than 18” above finished grade (dirt), then conventional wood framing can take over.

Concrete walls, no matter what anyone else tells you, are always damp and cold…always…in any climate and in any season. So, it makes sense (and cents) to switch to wood as soon as the finished grade allows.

As for the wood framed walls strength, there is no dirt pushing on the wood framed walls, no hydrostatic pressure either as the wood framing is above grade, so the wood framing is fine.

As for the flooding part of your question, I hope you mean minor flooding such as flooding caused by a leaky basement.

One of the main advantages of a walkout basement is the fact that with proper waterproofing and drainage, the chance of a flooded basement is greatly reduced.

The chance of flooding is reduced because rain and runoff water have gravity helping them go around the structure and drain away from the house on the side where the wood walls are “at grade”.

A sump pump is still required with a walkout basement by most building codes, so that tells you that a walkout basement is not immune to flooding.

But flooding is irrelevant as to whether the walls are concrete or wood.

Carl

We are purchasing a modular and need a basement put in. The modular is 27 x 65 feet. The walls of the basement should be 9 foot. We need someone in Michigan to give us a price quote.

Right now we just need a quick estimate (ball park figure) to get the loan started.

Thank you.
Laura

Hi Laura,

You should be able to find a qualified foundation contractor in MI without too much trouble. Your Modular dealer is the most likely place to find one.

You could also call a concrete supplier for a few names.

Get at least three bids from three different contractors and be sure to get (and check) references from them.

In the meantime if you want to get a rough estimate as to what the cost should be, read my article on “Basement Construction Cost”.

You’ll see how to use the “Building Cost Calculator” that’s on my “Getting Started” page to come up with a rough estimate of just the basement.

The shape of the outside perimeter is an important consideration in estimating the total basement construction cost.

Generally, the more complex the shape of the basement foundation, the more expensive the structure per square foot of floor area…Read the rest of the instructions on how to use the calculator to get just the cost of the basement (don’t forget excavation, permits, etc.) @ Basement Construction Cost.

Good luck and enjoy your new home,
Carl

Thanks, Autumn”

Hi Autumn,

You should read my page on basement insulation on www.byoh.com You are wise to be concerned about mold. Other problems such as wood rot can occur too.

Here is an excellent article on your problem from the Michigan State University Extension bulletin E-2109, Moisture Problems in the Home.

Adding insulation to basement walls has advantages similar to adding it to wall cavities and the ceiling: it eliminates cold surfaces where condensation can occur, and it cuts energy costs.

Basement walls are often insulated by adding furring strips to the walls and installing rigid or batt insulation between the furring strips.

If you use batt insulation, install a vapor retarder such as polyethylene film on the winter warm side of the batt insulation to prevent future moisture migration into it.

To achieve a finished effect, place drywall over the vapor retarder. (Note: There is some question about using a second layer of polyethylene when batt insulation is used on basement walls.)

Rigid insulation is relatively impervious to water and moisture vapor damage. Therefore, it does not require the addition of a vapor retarder over or behind it when it is added to basement walls.

As with batt insulation, drywall can and should be used over rigid insulation to provide a finished look and, in accordance with building codes, to provide a fire protective covering over the material that separates it from a habitable living space.

Keep in mind, too, that if condensation is occurring in the basement during humid summer weather, windows and doors to the basement should be closed to help keep the humid air out.

Open doors and windows when outside humidity levels are low to introduce dry air into the basement.

Seepage and leakage
Seepage or leakage problems commonly occur in the basement or crawl space in the early spring when snow and ice are melting and frost is beginning to leave the ground. They can also occur in the spring, summer and
fall during and after heavy rains.

Seepage in a basement is the slow (non-pressurized) movement of groundwater through the basement walls. It may appear as a damp spot in an isolated area or in many spots. Leakage, on the other hand, is the fast (pressurized) movement of groundwater through the wall.

In the case of leakage, the entry routes for the water are cracks or joints in the wall; with seepage, the water migrates through pores in the wall material.

Two conditions must exist for seepage or leakage to occur.

First, the soil near the basement or foundation walls must be wet or saturated.

Second, the basement or foundation wall must have a weak spot where water infiltration can occur.

Soil Saturation

Wet or saturated soil near basement walls can have several causes: improper disposal of roof water runoff, poor surface drainage away from the house, separation between the basement or foundation wall and the soil surrounding it (this crack acts like a funnel), window wells collecting rain water, lawn sprinklers located too close to the house, an inadequate below-ground footing drain system or a high water table.

Once the soil is wet or saturated, cracks, weak joints or pores in the masonry provide a route through the
basement or foundation wall.

Alleviate wet or saturated soil near the basement walls by minimizing or eliminating the moisture at its source.

The installation, repair and maintenance of the gutter, downspouts and eaves trough discharge system are necessary to minimize the ponding of roof water run off close to the foundation. Eaves trough discharges should terminate at least 3 feet away from the basement/foundation wall and gently slope away from the foundation at least 1 inch per foot of discharge run.

An adequate ground slope away from the basement/foundation wall is needed to ensure that rainwater will be distributed away from the foundation. Generally, a slope of 6 inches in a 10-foot run of ground is adequate. All pockets or openings between the soil and the foundation should be filled with clean material that has good drainage characteristics, such as pea gravel and sandy soil.

Window well covers should be installed so that rain-water will not collect in the wells. Locate lawn sprinklers so they don’t sprinkle the walls.

A sump pump can be attached to the footing drain tile(a building contractor will be needed for this unless you are an experienced do-it-yourselfer) to drain excess ground water away from the tile system and discharge it into a sump well set in the basement floor. In turn, the sump can then pump the waste water into the storm sewer system or to a ground area adjacent to the house.

Choose a spot where the water will not damage the foundation or any adjoining property. Contact your local township or city building officials for specific guidelines on where to dispose of sump pump discharge.

Again, read my page about basement insulation on www.byoh.com

I hope you are able to solve your problem,
Carl