How to Dig Out a Crawlspace

Make your life easier by digging out your crawlspace.

A crawlspace is a narrow space left between the ground and the floor of a building that allows minimal storage and access to pipes or wiring for repair and maintenance. Houses often have a crawlspace rather than a full basement, or because the house is located on a site where you cannot have a full basement (such as houses built at sea level). Consider digging out your crawlspace to gain a little more room, or to create a full basement. There are several steps and considerations you need to follow when digging out a crawl space in order to avoid damaging the integrity of your foundation.

Things You'll Need

• Tape measure
• Spray paint
• Shovel
• Wheelbarrow
• Mortar mixing pan
• String line
• Rope

Instructions

1. Figure out the range of support you need to maintain the integrity of the soil surrounding your footings, foundation walls and pilasters (if you have any). Do this by using the formula to figure out the sides of a triangle {a(sq) + b(sq)=c(sq)} using the depth you wish to dig for "a" and 3 feet for "b." "C" will equal the angle at which you can slope the dirt from the depth you have dug back up to the foundation, footing or pilaster.

2. 

   Measure and mark with spray paint the edge of the supporting dirt (backfill) you need to maintain around the foundation. Do not dig out the dirt between your mark and the foundation.

3. Dig and remove the dirt from your crawlspace. If you have enough room, use a wheelbarrow to carry the dirt out. If you do not have much room, use a large mortar mixing pan and drag the pan out to empty it. This will have less a risk of tipping than a bucket and will be easier on your back as well.

4. Run a string line across the crawlspace set to an equal distance down from the ceiling of the crawlspace. Use this line as the point from which to measure down to check that you are digging to an equal depth throughout the entire crawlspace. Work each section and check your depth frequently.

5. Slope the supporting dirt against your foundation back to prevent it from collapsing, but do not remove any more dirt than necessary. The angle of the slope will not be great, just enough to prevent it from crumbling and caving in.

Tips & Warnings

• Attach a rope to your mortar mixing pan to make it easier to pull out to empty if the crawlspace you are working in is very small.

• Do not dig the new depth of the crawlspace down directly alongside the foundation, footing or pilaster. You must maintain at least a 3-foot wide span of dirt, sloped according to the angle you found in step 1 in order to maintain the structural integrity of the foundation and of the support integrity of the backfill supporting it; if you do not do this, the weight of your house may crack the foundation.