Five Tips for Evaluating a Residential Foundation Before You Purchase

Five Tips For Evaluating A Residential Foundation Before You Purchase

Experienced homeowners and real estate investors know what to look for in a potential purchase, whether they intend to live there, flip a home or hold on to it as a rental property.  And one of the first areas they focus on is the foundation, which could be slab on grade, poured concrete, cinder block or even stone.  Here are some tips on evaluating and maintaining a solid foundation.

One – Walk Around

On your first visit to a property, walk around the exterior of the home with an eye out for cracks or flaking concrete.  Then poke around the interior of the basement if the home has one.  Take pictures so you can recall anything you see and describe it and its location to others.  I like to draw a simple location map of where cracks are detected on a 3×5 card as a reminder of what I saw.  Here is an example

Two – Moisture

Perhaps the most important issue with foundations is keeping the interior dry.  A careful inspection is required to identify any areas where moisture or water is present or has left telltale signs of entry in the past.

In many parts of the country where full basements are found, the combination of wide temperature changes and expansive soil (such as clay) will put pressure on the foundation walls.  Over time, cracks will develop. It is estimated that 60% of all poured foundations will develop cracks at some point, though some of these cracks may not leak. 

If you are rehabbing a home that may be several decades old and which has a finished basement, you should strongly consider removing the drywall, paneling or other wall coverings to ensure that any cracks and leaks, which you are very likely to find, can be inspected and sealed. This becomes a must if there are visible cracks on the exterior or any evidence of water on the walls, floors or carpet inside the basement.

Another telltale sign of moisture is the presence of efflorescence on walls, usually near cracks or where walls meet floors.  This is a white powdery deposit and is caused by soluble salts and minerals leaching from the concrete.  It is a sure sign of moisture in the wall and if a leak is not visible now, it likely will be at some point.

Don’t forget to inspect the Water Access Point where the main water line enters the home.  The holes drilled through the wall to accommodate the waterline are notoriously poorly sealed, but can be repaired quite easily.

Most cracks in poured foundations can be sealed with expanding polyurethane or repaired with carbon fiber products where either cracks are wide or extra strength is required.  Importantly, sealing the cracks may delay or prevent bigger and more expensive problems such as bowed or leaning walls.

If the foundation is built with cinder blocks, Concrete Masonry Units (CMU’s) or stone, your best move is to bring in pros who have experience with masonry.  The unitized construction with cinder blocks and the mortar used with stone require special materials and techniques for proper repair.  The exception is that if you find a “bowing wall” in a cinder block wall, it can be repaired with carbon fiber straps if the displacement of the wall is 2” or less.  See the discussion below for additional information.

If you find moisture or water but no cracks or obvious sources, you should investigate the possibility of groundwater entering through the cove joint between the floor and the wall.  This is less common but may require an interior drain to be installed.

To keep moisture from pooling under the home, creating pressure and eventually entering the basement, a working sump pump is recommended.  And if you are going to put one in, go the extra mile and install a battery backup.  Without this protection, you could end up with big issues.  The very night when a storm rages and the electricity goes out, your sump pump will become useless without a contingency for power,  and you or your tenants will have a basement full of water.

Three – Structural Integrity

An important issue when evaluating a residential basement foundation is the integrity of the structure.  Bowing and severely cracked walls, especially those with horizontal cracks or cracks that are wider than 1/4 inch, often require more specific inspections and more extensive repairs.  A bowed wall usually has a long horizontal crack and the area nearest the crack has moved inward.  First, determine how far a wall has moved.  If that movement is less than 2 inches then consider carbon fiber straps which can arrest further movement at a reasonable cost.  To make that determination take measurements above and below the horizontal crack. More than 2 inches of movement will almost always indicate a need for braces or anchors. Here is a recent bowed wall repair with carbon fiber straps. augmenting earlier repairs with steel braces.

If any of the walls show significant movement or obvious damage, you should retain a structural engineer to assess the home and recommend the correct solution.  This will cost several hundred dollars but is often worth it.  Having a written structural engineer’s report and receipts and warranties from contractors will go a long way to address any apprehension a potential buyer may have.

Four – Mold

It is often the case that where you find moisture and water that you will find mold.  And don’t forget that often mold may be unseen.  If there is frequently water in the basement or you see an active leak from a crack or a water line, an air test is recommended.  Enlist the services of a qualified mold remediation service to take air samples and determine how extensive the mold is.  They will also determine what wall coverings, carpet, and furniture must be removed or disposed of and how best to clean the area so that people can use it without risking their health.  There are several new techniques that avoid the use of harsh chemicals and are therefore safer for people, pets and plants.

Five – Radon

For several decades, the presence of radon has been top of mind in home inspections.  Researchers believe about 6% of homes may have elevated levels that require intervention. Radon is a radioactive gas, but because it is odorless and colorless only testing can detect and measure it. Radon technicians usually place measuring devices in the basement for several days to determine if the levels require attention. 

Sealing a basement is not sufficient for solving a radon problem.  Mitigation involves the capture and venting of the gas. Radon mitigation equipment can be installed as a stand-alone system or may be integrated into a closed sump pump.  The advantage of having a radon mitigation system and a sump pump is that when you decide to sell the home, you will give potential buyers greater confidence that the basement is healthy, and you will have one less thing to worry about or pay for.

It is almost always the case that the sooner you deal with foundation issues, the appropriate repair will be less extensive and therefore cost less.  My experience is that residential basement foundations rarely heal themselves and procrastination with regard to inspections and repairs is not your friend. Investing in ensuring the safety and health of the foundation is just good practice when purchasing and remodeling a residence, whether you or someone else will live there.

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