In the latest episode of Real Estate 101: The Home Buying & Selling Show, Daniel Ott, President & Lead Designer at White Willow Design talks about home renovations and what homeowners can do if they want to lower their basement floor.
Why Would You Lower Your Basement Floor?
Lowering a basement floor is a good way for homeowners to get more headroom. There can be a number of reasons why someone would want this. One of them includes making a basement apartment. For this, the basement would need to have a minimum height set up by the building code to be accepted as “livable space”.
To reach that minimum height, you will need to lower the basement floor to get the height difference between the underside of the joist and the top of slab.
How Do You Lower a Basement Floor?
You will first need to take out the concrete floor, the gravel beneath it and then dig out the dirt underneath the gravel. How much dirt you’ll have to dig out, depends on how far down you need to go to reach the minimum height requirement.
Once you know how far you need to dig down, you will need to dig the dirt to a level about 8-10 inches lower than where you want the end floor height to be. On this, you need to fill in 5-6 inches of gravel and an additional 3-4 inches of concrete floor.
However, if you need to lower your basement floor more than a couple of inches, things get a little complicated. This is where “underpining” comes in play. This means removing the footings underneath the walls, removing the dirt underneath that, pouring new footings and finally filling in the void.
This can’t be done all at the same time and is typically done in sections. Usually this is done in 4-foot sections where you first remove the footings and dig down, leave four feet, dig another section and repeat the process for the entire basement floor. After that, you can build where the voids are, remove the other sections and build where those are.
Another and more cost-effective and less labor-intensive way to lower a basement floor is called “bench footing”. This method can be done all at once and requires digging down on a 45 degree angle. This allows the weight to be distributed through that angle and prevents disturbing the dirt that’s actually holding the house.
The main drawback of bench footing is that the lower you have to go, the more space you will take out of your basement floor. So, if you need to dig a few feet down, “underpining is probably the better choice.
Watch this episode to learn more about basement floor renovations.
How Much Does it Cost to Lower Your Basement Floor?
Lowering the basement floor can cost around $40-50,000 for a medium sized basement if you’re doing underpining. For bench footing it would be around $10,000 or more.
For more information on home renovations contact:
Website: White Willow Design
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