There are many things you need to know about foundation slab and underpinning. If you have a
basement, it is important to know that finding a floor will not be easy. There is a layer or masonry
between the basement’s floor and sub-floor. Even with the use of masonry walls, a basement is
still cold and usually wet.
One of the most common ways to repair a basement is by putting in a crawl space. With a
regular foundation and with proper underpinning, the masonry layer can be removed and the
floor made level and ready for the next step. A basement is a damp area. The water tends bead
up from ground and pool around the house, and can make a otherwise dry basement moist.
The foundation and the underpinning are used to keep the water from reaching the foundation
and the interior. The crawl space floor is different from any other floor in the house. It has an
extra drain, with a special pump. Water seeps into the soil on top of the slab and flows to the
drains. The underpinning and foundation slabs keep the water away from the foundation, and
the floor and sides of the slab are sealed to keep water out.
Underpinning refers to the fact that the foundation slab may not be completely solid. While most
foundations aren’t solid, it doesn’t mean the house can’t. The foundation slabs cannot support all
the house’s weight. The slabs can bend or buckle if they are not strong enough and water can
enter. The pressure on this water can cause problems with the house’s integrity and eventually
cause cracking. Cracks may indicate foundation problems that require attention, but it is not
necessary to have underpinning.
Your foundation slab and underpinning may need to be adjusted if you have foundation
problems. An underlay is an additional structural reinforcement for the foundation. Engineers
refer to this additional structural support as “box strength”. The idea is to make the house resist
collapse in strong winds. Otherwise, if the house were to collapse, the structural supports would
break, which could cause the whole thing to cave in, causing the foundation to bow and
potentially leading to structural damage inside the house.
You are actually adding another floor to the ground by removing the foundation slab. You might
think you are raising the floor higher than it should be because you have added structure above
the ground. But when it comes to the structural supports in the floor, you are in fact decreasing
their load-bearing capacity. Underlining can also weaken the foundation and increase the
chance of it failing. It can lead over time to cracks and buckling that can lead into movement and
increased energy bills. You can increase the likelihood of foundation collapse if you don’t have
the right underpinning or foundation slab.
You are reducing the space under the house for water and increasing drainage problems by
lowering the foundation. There may be water accumulating in the basements which can cause
damage to the interior of your house. You want to make sure that any underpining you do
provides maximum protection against natural forces, not just for aesthetic reasons but because
you don’t want the home to become damaged.
It is crucial that you continue to work after you have weakened the foundation. If you do not, then
you run the risk of the structure becoming weakened over time and collapse. Foundation slabs
cannot be removed so it is essential to seal them. Sealing the slab will make the structure
stronger, more resistant to natural forces. The foundation slabs won’t crack, break, or move
if you seal them. If you feel that underpinning is not enough to protect your home then consider
adding sealants to help prevent moisture from entering the basement.
