Can I build a house slab on grade?
In some areas the building code does allow for you to build slab on grade homes. But in most northern regions of North America there are heavy restrictions on building a home that is slab on grade.
The reason for the heavy restrictions or the outright ban on building this way is that slab on grade foundations have little to no frost protection. The problem with not having adequate frost protection is that in a cold winter you can have the frost penetrate the ground around the house and then have it travel underneath the slab. As the frost takes hold it moves the ground, this movement in the ground is so powerful that it can lift whole foundations.
When a foundation has been lifted it isn’t the entire foundation that rises together, only part of the foundation will be moved up. This causes twisting in the slab, twisting causes the slab to break and it also causes stress on the rest of the building envelope that is resting on the slab. This will cause damage throughout the home.
The damage is not only in the foundation or the foundation walls it can also cause the following;
• Drywall damage. Cracking, nail pops and tape joints letting go as the walls twist.
• Decks go out of level as the walls they are attached to go up and down.
• Floors in the home are not level from one side to the other.
• Doors and windows in the home start to stick or jamb.
• Tile floors crack or brake.
• Wood floors cup or crack.
• Cabinet doors don’t stay closets or don’t close at all.
• Granite counter tops crack or break.
• Gas lines can be ruptured.
• You can lose electricity as the power lines are stretched or pulled out of the electrical meter.
• Break or block can crack or fall off the outside walls.
When the winter passes and the frost recedes the house will settle back to it’s original position but the damage that it has caused will stay.
Without a proper foundation that is placed so that it reaches below the frost line there is no way to guarantee that your home will not move from frost heave.
Village Builders Inc.