Is it better to fix foundation cracks from inside or outside?

Author: Roy Waters  |  Last update: Wednesday, June 24, 2026

Cracks can be sealed from either the interior or exterior of the foundation. If done right, either way is equally effective. If there's a deck or patio in the way, or your basement is unfinished, it's more common to seal cracks from the interior.

Can you seal a foundation crack from the inside?

You can seal on the inside through a qualified foundation repair company, but I would also recommend exposing it on the outside and using a blue skin membrane or similar to seal the crack.

Can you fix a foundation leak from the inside?

My experience with foundation leaks is that fixing from the interior is temporary. Eventually water will find its way in again. If there is pressure, it will find its way around. Permanent fix should be from outside which is where the problem is.

Are exterior foundation cracks normal?

Some cracks in the foundation, including hairline cracks, are considered normal foundation cracks. These typically appear due to settling or concrete shrinkage. Other types of foundation cracks might indicate a serious structural problem.

Should I water my house foundation to keep it from cracking?

When there has been no rain, it is very important to water your concrete foundation. Dry foundations can cause cracks in walls, doors shifting or won't close or stick when you try to open them. The trick to avoiding a shifting foundation is to keep the perimeter of the foundation evenly moist.

What Kind of Foundation Cracks Are BAD??

Can you fix foundation problems yourself?

No. While it may be more affordable than professional foundation services, DIY foundation repair is not a good idea. Fixing foundation problems is best left to professionals.

Can you waterproof a foundation from the inside?

Interior basement waterproofing involves waterproofing basement walls from the inside. This way, the water that leaks into the basement is re-routed, before it can come in, out and away from your home. It is an effective waterproofing method and a much less offensive alternative to exterior waterproofing.

Does homeowners cover foundation leaks?

Homeowners insurance may cover foundation damage, but it depends on the cause. Coverage typically extends to sudden, direct physical loss but typically not wear, tear, and / or deterioration. Early detection of foundation problems is critical.

Should you fill in cracks in foundation?

No, not all foundation cracks need to be repaired. If the cracks are very small or caused by settling, they can usually just be filled and painted over.

Can you seal a concrete foundation from the inside?

To waterproof your basement from the inside, apply a high-quality masonry waterproofing product to the interior walls. Once the coating dries, it creates a strong, watertight barrier that prevents water from penetrating the walls.

How do I know if my foundation crack is structural?

Cracks wider than ¼ inch or those that are horizontal are known as structural foundation cracks. As the name indicates, these cracks pose a severe threat to the structural integrity of the foundation.

What is the most expensive foundation repair?

Depending on the type of issue, foundation repairs can cost as little as $250 for minor cracks and upwards of $25,000 or more if the issue requires hydraulic piers.

How do you seal interior foundation cracks?

There are two main components of foundation crack repair and those are epoxy and polyurethane foams. The concept is to use a tool similar to a caulk gun to inject the material into the crack. The foam goes in as a liquid and then expands and hardens to fill the crack.

Can you live in a house during foundation repair?

You won't need to leave your home while foundation repairs are taking place. So, living in a house during a foundation repair is the norm. Yes, there will be some noise from hydraulic pumps and generators from the work being performed. However, in some cases, you won't notice much disturbance overall.

What is better, interior or exterior waterproofing?

Structural Protection: By preventing water from penetrating the foundation, exterior waterproofing safeguards the structural integrity of the building more directly than interior solutions, which primarily manage water once inside.

How do you seal a foundation from the outside?

How to Waterproof House Foundations From the Outside
  1. Step 1: Excavate the Soil Around the Perimeter of your Foundation. ...
  2. Step 2: Clean and Prep Your Foundation Walls. ...
  3. Step 3: Fix Damage to Your Foundation Walls. ...
  4. Step 4: Apply a Waterproofing Membrane to the Outside of the Foundation. ...
  5. Step 5: Install Window Wells.

Can I use flex seal in my basement?

Apply Flex Seal Products

Flex Shot and Flex Seal Liquid are great options for attacking a basement wall leak.

How expensive is it to fix a cracked foundation?

Foundation Cracks – Repair Cost

Most crack repairs cost between $200 and $1,000, with the average cost falling around $600. Cracks narrower than ⅛” are fixable with epoxy filler, and it's generally considered safe to do yourself.

When can a foundation not be repaired?

This can occur for various reasons, including a catastrophic natural disaster or a long-neglected foundation problem. In other words, a foundation needs to be in really bad condition before it's beyond repair.

What can go wrong with foundation repair?

Unfortunately, residual damage isn't uncommon and you can't count on all cracks to close. In our experience, in about 70% of cases the cracks come together, 20% the cracks stay the same, and the rest worsen. In fact, as the foundation settles into its new position new cracks can appear.

Should foundation cracks be filled?

No matter what has caused the foundation to crack, or whether it is moving or static, the crack should be sealed. Sealing the crack correctly will preserve the integrity of the wall and also prevent water from entering into the space within.

How long should I run my soaker hose around my foundation?

Use the hose 3 to 5 times a week for about 15 to 20 minutes each time – you may need to adjust this schedule if the summer is unusually hot or dry. An automatic timer can really come in handy here. Check the soil's moisture level from time to time – you want to make sure that it's moist but not muddy.

Should I fill a gap between foundation and soil?

We are getting a lot of phone calls regarding this space between the edge of your foundation and the DIRT. 🛑 Do Not fill it with Dirt 🚨 Do Not stick a hose down in the crack. Soaker hoses or a drip line are the only safe way to gradually bring the soil back to support the foundation.

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