Can You Finish A Basement With A Stone Foundation? [And How To]

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Regardless of the type of foundation, it is best to finish your basement, as you surely want to create a more livable space for your family activities. However, if you have a stone foundation, there are problems like moisture and water seepage to address. But don't worry. We've researched expert tips to help you with this basement concern.

Yes, you can finish your basement with a stone foundation. The process starts with assessing if there are repairs needed for the foundation. Finishing will involve reinforcing and repointing the stones to maintain the foundation's strength. Sealing and waterproofing are also vital to keep the basement dry.

One major reason it can be challenging to finish the stone foundation of your basement is its age. There could be severe damage present in the foundations. Even though it is a tough job, the benefits of finishing add function and value to your home. Continue reading for more details on finishing your stone basement.

A dark basement with stone wall, Can You Finish A Basement With A Stone Foundation? [And How To]

Is It Possible To Finish A Stone Basement?

Although it is possible to finish a stone basement, it will be a challenge to do so. You would encounter varying issues with different stone foundations. Some causes of damage include age, mortar choice, and weak construction. It is best to start checking the current condition of the basement first.

Listed below are the common signs of stone foundation problems:

  • Mortar is crumbling between the stones.
  • Stones are always wet or trapping water.
  • There is evident bowing or curving of the walls.
  • The walls have cracks and holes. Pieces of stone are falling off or spalling.
  • Efflorescence is leaching between the stones.
  • You can see moss growing on the foundations.
  • The parging on the exterior of the stone foundation is deteriorating.
  • You will feel that the surface of the stones is coarse and shedding excessively.

If these signs are present in your stone foundation, you have to add new mortar, repoint some stones, and reinforce the foundation. It will also help to do proper sealing and waterproofing of the foundations. After you assess that there are no more issues, you can proceed with finishing.

How To Finish Your Basement With A Stone Foundation

Bathroom in basement of house

Here are the steps to finish your stone basement:

  1. Repair the damaged mortar joints and add new mortar.
  2. Add coatings of sealer and chosen masonry waterproofer. You can also waterproof from the outside or add interior drains.
  3. Patch hydraulic cement for parts that still have some moisture.
  4. Then install suitable insulation. You can use XPS or EPS foam. It will also help to choose insulation with vapor barriers.
  5. Coat with an insulating mortar for the foam board.
  6. If you want to hide the stone foundation, you can also cover this with wooden planks, plastic panels, or plaster. You can do without this step if you want to retain the rustic feel of the stones.
  7. You can paint the stone foundation to enhance its appeal.

You can also check out our previous post to see if you can finish a fieldstone basement.

Can You Add Concrete Over A Stone Foundation?

You can add concrete over a stone foundation. By doing so, you can reinforce the foundations to avoid collapsing and related damages. You will need some reinforcement if your place is prone to natural hazards and frequent rainfall.

Parging involves the process of applying a cement coating over masonry stone or block foundations. There will be different concrete mixtures depending on your needs. You can create a smooth surface that makes a neat-looking basement.

You can either pour concrete or add concrete blocks to get a new and flat foundation. If you want to keep the rugged appeal of the foundation, you can add some footings instead.

Do Stone Foundations Have Footings?

Barn stone foundation

Stone foundations do not have footings to support the weight of the house. This type of foundation relies on the strength of large and flat stones underneath. Without footings, the foundation adjusts to the swelling and settlements on the ground when seasons change.

It will still be essential to add some footings that support the structure and transfer the load to the soil instead.

Adding Footings

If you want to add footings for the foundation, you can do so. You have to excavate a trench that is 3 to 5 feet deep. The width depends on the load and properties of the soil.

For stone footings, look for hard and durable rocks like granite, laminated sandstone, or bluestone. The stones' thickness should be at least 1/4 of their width. You also need to wet the stones to prevent absorbing water.

There is also a plain concrete bed that you need to set at the bottom of the foundation. Then add a layer of mortar mixed with cement on the concrete. From there, arrange the stones close to each other and stagger on the joints. The smaller stones will fill up gaps. Lastly, add mortar to cover the footings.

How To Keep A Stone Basement Dry

Regardless of foundation type, moisture is a major problem in basements. Even though stone basements are long-lasting, they are not waterproof. The aging of the foundations allows water to trickle down on the stone. When there is water seepage, it causes structural damage to the basement.

The soil around the foundations can also cause water and moisture to come into the basement. When the soil has too much water pressure, it can create cracks where water can pass through.

But don't worry. Here are the common methods to keep your stone basement dry:

  • Sealing - You can prevent water and gas seepage when you apply coats of masonry sealant.
  • Interior waterproofing - This method includes adding drains, vapor barriers, and waterproofing sealants.
  • Exterior waterproofing - You might need to excavate the exteriors of the foundation. This method involves adding new mortar or a waterproof membrane.

Find out what to do when there is water leaking in the basement after heavy rain.

How To Seal A Stone Foundation Basement

Sealing your stone foundation helps in keeping your basement dry. Although tough, a stone is a porous material. You can avoid the moisture buildup that causes structural and health issues to your family.

Here are the steps to follow when sealing stone foundations:

  1. Clean the stone wall with a mild solution. Use a soft sponge to wash the wall.
  2. Pat dry the wall with some cloth. Then leave it to dry overnight.
  3. Repair broken mortar joints. Let the mortar dry for at least 2 to 3 days.
  4. After drying the mortar, work in a sealant to the mortar joints. Wait for 2 to 4 hours before proceeding.
  5. With a paint roller, apply at least 2 to 3 coatings of the masonry sealant. The drying time will take at least 48 hours.

How Much Does It Cost To Seal A Stone Foundation?

You should also know how much you are going to spend on sealing a stone basement. The sealing costs range from $500 to $10,000. If you have complicated foundation issues, it can cost you more. Your costs will also depend if you do the sealing on your own or ask for professional services.

Here is a breakdown of the costs included in the estimates:

  • Concrete sealer - A gallon can cost around $100.
  • Waterproof paint - This will help keep moisture out from the basement. A gallon costs around $30-40.
  • Labor costs - The charges include the cleaning and applying of the sealer. The cost is about $3-12 per square footage. If you choose a silicate sealer, it will cost $3-9 per square foot.

Make sure that you select high-quality sealants and materials to get the most out of your money. If you can keep your basement dry for a long time, the costs will be negligible.

In Closing

It is possible to finish a stone basement. Even with the issues brought about by the age of the foundation, you can still repair and reinforce them. You can fortify the stone foundation by parging and adding footings with concrete.

It is also important to seal the foundations to keep the basement dry. Sealing stone foundations is easy but costly. High-quality sealants can be expensive, but the benefits will help you maintain the basement condition. By finishing your stone basement, you can create a suitable space for your family.

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