basement floor

Miscellaneous Inspection Topics AskNACHI.org Questions
1

What product can I put on the floor that will help in keeping my basement
> warmer? Its always cold and damp but there is no water infiltration. I have
> just gutted the whole basement and there is no dampness anywhere other than
> a couple of white powdery areas. I would like to seal the floor, if
> possible, with a product that will help as I know that there is nothing that
> will actually keep it really warm, other than sub floor systems.
>
> Thanks for your help
>
> Pierre

2

You can not water proof the floor from the inside .
If you do not have a sump pump you need one try and keep the water table at lease 12 inches below the bottom of the cement .
You do have dampness if you see efloursence
(the white powder) You should have a dehumidifer to keep the moisture level below 50%.
I have found (http://www.dricore.com/en/eIndex.aspx) works well, Follow the directions all the way…
There are no short cuts do it proper and do it once , A small circulating fan will help to limit cool areas.
Roy

3

Pierre, Roy is correct. It is hard to make an accurate judgment off of a forum post:)

There are a number of plastic dimpled products that allow you to place OSB or Plywood down without touching the concrete. (which would be bad) This helps prevent direct conduction of the cold concrete into the basement.

4

This helps prevent direct conduction of the heat from the room into the concrete and soil below and acts as a moisture barrier to stop evaporation of moisture from the slab surface.

5

There are no easy fixes to basement problems. Hope this helps.
The previous replies are correct. It is very difficult to seal a basement from the inside. However there is a product available on the market that goes a long way to do this. Please check out the website:
www.barriercoatings.com Look for a product called Ultra Guard. It is without a doubt the most effective product available to do an impossible job.

Weeping Tile and Sump Pumps

The lid to the sump must be securely fastened at all times. Never leave it open or unfastened.
You will note that your new home has a sump in the floor in the laundry room. The following is information you need to understand about the drainage system in your new home. Every home has water under the floor, it is a natural occurrence, and there are measures put in place to deal with this water.

  1. The first line of defense against water coming into a basement is the weeping tile. This is 4 inch perforated plastic hose that runs the entire perimeter of the basement below the basement floor; it is then connected to the floor drain or sump reservoir depending on municipal regulations. The purpose of the weeping tile is to gather water that might collect in this area and direct it to the floor drain if connected to the sanitary sewer system or pumped out side if connected to a reservoir. These reservoirs are often mistaken for sumps. They are not sumps, because they to not allow ground water to enter other than that which flows in from the weeping tile.
  2. The second line of defense is the rock base that is placed under the floor. Your entire basement floor has a layer of rock. This rock allows for any water that might collect under the floor to find its way to the weeping tile and subsequently it will be dealt with as indicated in one above.
  3. Most contractors stop at this point. Our company goes one step further and installs a sump a “true sump” one that deals with water well below the floor.
    a. This sump is approx 6 feet deep, 20 inches in diameter (Capacity is approx 80 Imperial Gallons). The sump has approx 2000 holes and is wrapped in a “nonwoven geotextile material. This unit is packed in crushed rock. This system allows water to flow freely into the sump without allowing particles of soil to enter the sump. There are connections to the floor drain and to the outside. The sump has three pumps located inside
    i. It is critical that we do not pump soil out from under the basement floor, because eventually it would collapse your floor and your house. Consider if the sump were to let in 1 cup of soil per day. In 10 years it would pump our 30 cubic feet of soil from under the floor.
    b. Pump # 1 is connected to a line that runs to the outside of your home, this allows ground water to be pumped outside and away from the basement.
    c. Pump #2 is connected to the sanitary sewer system, and allows water to be pumped into the sanitary sewer system.
    i. These pumps are plugged into a control box that that directs power to one or the other depending on the outside temperature. If the temperature is below 5 degrees C or 40 Degrees F then the control will feed power to pump #2 and the water will be discharged into the sanitary sewer system. If the temperature is above 5 degrees C or 40 Degrees F then the control will feed power to pump #1 and the water will be discharged outside the home.
    d. Pump # 3 is a battery backup pump pumps water to the outside of the house. It is assumed that if the pump is called upon to pump in the case of a power failure it will likely be on a warmer day when it is raining and therefore the pump will pump outside.

Why is the sump so deep?

  1. Water will find its own level so in theory if you put a sump in that is say 24 inches deep you should be safe. NOT. The pump will not hold the water at the bottom of the sump, so at best you can expect that the water level given enough time will be a min of say 12 inches under the floor at the sump location. For every foot you move away from the sump this level will move closer to the floor, and in fact you could have water problems in another corner of your home.
  2. Sumps should be 6 feet deep and approx 20 inches in diameter. There are a couple of reasons for this:
    a. First off if the pump is activated when the water level is say 5 feet below the floor, you should be guaranteed that during less rainy times the level of water under your entire floor will be well below. This means that you actually have a very large reservoir that will fill before you get any water in your basement. You have the sump reservoir as well as all of the space under the floor. As soon as the water level reaches a point that will turn on the pump it gets a head start on holding the water below the basement floor.
    b. The size of the reservoir is critical because it means that the pump will run longer and less frequently.