There’s no way you can restrict basement water intrusion, you think you can, but you have no idea about the enemies the basement walls are fighting against. The groundwater coming up from underneath, rainwater falling against the walls, window wells filling up, soil moisture, etc., is continuously taking down the strength of your exterior basement walls.
Yes, you can’t deny the water intrusion, but you can try your best to put up your best card for protection. The earlier you take the protective measures, the better security you can offer. So, what do these methods of waterproofing exterior basement walls cost? You can’t deal with the battle unless you know the resources you need. So, let’s hop on.
Reasons for Damp Exterior Basement Walls
If you need to solve the water intrusion issue, you need to find out the problem that’s causing it.
Gutters and incorrectly installed downpipes
If your house faces foundation wall leaks, rising wall moisture, or flooding despite having gutter and downpipes installed, it indicates improper installation. Instead, drains should be placed around the foundation with the soffits; they retain the rainwater and carry it to the downpipes, ultimately taking away the water.
Leaks in the plumbing allow water or moisture drips into the basement. If it’s not taken care of, not only will it result in basement moisture, water accumulation but also form molds and mildew.
Foundation cracks and pores
Cracks are a significant reason that lets water in your foundation. Well, your foundation is in great danger from any cracks that are larger than 1/8th of an inch. Although cracks are natural, especially in the first few years after construction, you must take measures against them as soon as you notice them.
Window wells collect water dripping against the facade and create a water pool that stands against the foundation. This is one of the most common reasons for water intrusion if you don’t drain the water regularly.
Coastal homes or homes in flood-prone zones are at severe risk of groundwater damage. This is because the natural water found in the foundation’s soil slowly seeps into the foundation through pores and cracks. Ultimately, it causes water intrusion into the foundation and basement.
Waterproofing Vs. Damp Proofing
Most times, people confuse the two terms. If you fail to differentiate them too, I’ll explain it to you-
Waterproofing: If your house is located in a flood-prone, moist or coastal area, it needs heavy protection against water intrusion. This waterproofing method is well-suited for poured foundations, cinder blocks, and waterproofing membranes, etc. Waterproofing costs an average of $5-$9 per square foot.
Damp proofing: This is a standard method for battling against high humidity and average rainfall. However, this cannot be a good solution for heavy rain or flood-prone areas. Dampproofing means preventing soil moisture from seeping into the foundation, and the cost ranges from around $3 to $6 per square foot.
Per Square Foot Cost Of Basement Waterproofing
- The average basement wall waterproofing cost ranges from about $4 to $7 per square foot.
-If you want more intense action with a more significant barrier, including more reliable waterproofing methods, then the cost can jump to $6-$10 per square foot. Depending on the level of water intrusion and more protection, the price will vary. For instance, when you need to install a sump pump or a waterproofing membrane, the price will increase.
Basement Sealing Cost
If we look at the total sealing cost of the basement, it will range from $1300 to $4500. Besides the minimum, there will be an added excavation cost of about $3500.
If you need to seal the foundation from the moisture in the soil that will ultimately resist water intrusion, below are some of the methods. But, first, let’s check the cost.
Cementitious sealant indicates sealing the foundation with a cement solution. It is a durable coating you can apply like paint giving you an even look at the end.
Although it works great for patches and covering crawl space, it’s not the best for covering cracks in the joint movements. The reason is the cement solution is relatively rigid. Cementitious sealant for your entire basement walls will be an average of $5.5 per square foot, including the labor cost.
Foundation waterproofing membrane
If you want a more effective solution, it would be to install a foundation waterproofing membrane. This method consists of excavation, installation of drainage panels, backfill, etc. The cost for such waterproofing membranes ranges from $3.5 to $7 per square foot.
Sheet membrane waterproofing
A sheet membrane is usually made of rubberized asphalt wrapped around the foundation, sticking to the walls. Things to know about the sheet membrane –
- It should be linked with the drainage system around the foundation.
- More care is needed to apply it over the joints and holes.
- Make sure your contractor uses about six inches of soil to cover the basement system.
- Do not delay in backfilling the excavated area.
- The per square foot cost would range from $3.7 to $6.5
Liquid membrane waterproofing
A liquid membrane waterproofing indicates the application of an elastomeric or crystalline membrane. Things to know-
- It needs about 2-3 coats of the crystalline membrane.
- The membrane is available in a variety of grades to protect against different levels of water intrusion.
- You need a professional to apply the membrane; otherwise, it will be uneven surrounding the whole foundation.
- The cost for liquid membrane waterproofing ranges from $3.4 to $5.8 per square foot.
Sodium bentonite waterproofing
It includes creating a layer of corrugated cardboard and clay, nailing them against the foundation. Things to know-
- This is not a permanent solution for keeping out the water as the clay may clog the drains.
- The average cost would be about $4
You can also opt for exterior excavation that would cost around $100 to $300 per linear foot. The price depends on the difficulty level and the higher depth you want. Besides, the minimum labor charge for excavation would be about $3000.