Looking at the basement concrete floor.

Very Happy Saturday to all,
We have looked at finding a contractor and examining the foundation walls, today we will take a closer look at the basement concrete floor.
Again if you live in Toronto and you live in an older house your concrete floor was poured a little different from a new home in the GTA or a newer one in Toronto. The concrete floor was only a couple of inches thick and it was poured directly over the dirt floor. Today a concrete floor is a minimum of 3 inches thick and is poured over  4 inches of 3/4 in clear gravel that is spread out over the dirt basement floor to allow for drainage. With a concrete floor poured directly over the dirt you will always have the moisture from the dirt  wanting to saturate the concrete floor. If you have an old concrete floor you will also have some deteriorating of the concrete and it will become very porous and there will be more capillary action happening in those locations. The older concrete floors usually have a lot of undulating areas which makes it difficult for installing laminate flooring. Sometimes there might be hydrostatic pressure that will cause the concrete floor to rise and crack which further complicates the installation of a finished flooring.
There are a few options that we have and depending on your budget you could choose the one that is right for you.
Option 1. Remove the entire existing concrete floor, excavate a further 4 ins of dirt, spread 4 ins of 3/4 in clear gravel and then pour 3 ins of concrete over the gravel to have a new concrete floor. With today's prices it could run you around $15.00 per sq. ft. for a project of this magnitude.
Option 2. Execute the same process as Option 1 but before you pour the concrete slab, you could add 2 ins of blue Styrofoam over the gravel then pour the concrete. This means you will have to remove an extra 2 ins of dirt when removing the concrete floor and existing dirt.
Option 3. Break up and remove the high areas of the concrete floor then remove the areas where the concrete has deteriorated. The broken up areas could now be fill with a premixed concrete stone mix by just adding water. To level the lower areas if it is quite large you could use a sand and cement mix with a concrete adhesive. First spread the concrete adhesive directly to the concrete floor and let it set until it is tacky to the touch. If the floor is very smooth it is best to make a few chip marks on the surface of the concrete to allow better adhesion of the new surfacing concrete. Next mix a slurry mixture with the cement and concrete adhesive and brush that on over the concrete adhesive. Mix the concrete and sand  together with the concrete adhesive and water and level the areas of the floor that are lower to achieve a level floor.
This is a very inexpensive method of levelling a large area of concrete floor. Toady's cost will be approximately $3.00 a sq. ft.
For smaller areas you could use a premixed floor leveller, such as SikaTop 122 or 123 Plus which is a polymer-modified, plus migrating corrosion inhibitor, cementitious, two-component fast setting mortar. It could be spread as thin as 3mm. ( 1/8 in ) and as thick as 38 mm. ( 1/2 in thick.)
There is also a Mappie floor leveller that works very well. If you use these products for large areas you will have to increase you budget for levelling the floor.
After levelling the concrete floor and you want to make sure that you won't have moisture damaging your newly installed flooring you could add a sub floor. There is a Dry Core sub flooring that comes in 2 ft x 2 ft interlocking squares that has a Delta membrane attached to the underside. This is an effective and inexpensive way install a sub floor. If you have a contractor do the work of supplying and installing the sub floor it could cost you around $4.00 a sq. ft.
Hope that this Blog have been helpful. If you have any questions feel free to contact me at 416-885-3987.
Next time we will chat about underpinning the basement or lowering the basement floor.

Jerome Sammy
416-885-3987
http://www.fbscto.com/
info@fbscto.com