Foundation Maintaining a dry basement is critical for the prevention of basement mold and mildew. Mold and mildew need moisture to develop and grow, and by creating and maintaining a dry basement you can prevent these insidious fungi from affecting the health of your family.
To maintain a dry basement start by examining the outside of your home. Make sure the soil grade sheds water away from your home’s foundation.
Also inspect the gutters and down spouts to make sure they direct water away from the home.
Next inspect the inside of the basement. In particular focus on the basement walls and floor. Look for foundation cracks and signs of water infiltration. Look for water stains, particularly around the bolt depressions that held the concrete forms in place when the basement was poured. If necessary seal any cracks in the foundation or in the bolt depressions if you see any signs of water stains.
If you are aware of a persistent water problem that prevents you from maintaining a dry basement, then consider hiring a basement waterproofing company. They may recommend sealing the exterior or interior of the home’s basement foundation. In addition, they may require the installation of a French perimeter drain system around the basement foundation.
Once you have tackled the big items for maintaining a dry basement, next check out all of the plumbing pipes.
Make sure there are no slow leaks. In addition, add pipe insulation to all of the supply line pipes to prevent condensation during hot and humid weather. Also, make sure the clothes dryers and any basement bathroom ventilation fans are vented to the outside.
Once you have taken all of these measures for maintaining a dry basement, purchase a dehumidifier and use it regularly.
It is important to use it daily during hot and humid times of the year when moisture levels in basements tend to be higher.
Finally, buy a circulating fan and use it frequently in the basement. By circulating the air in the basement you will maintain a dryer basement, and help to prevent the growth of mold and mildew.
Your foundation is your home’s infrastructure. It supports the floors, the walls, and the roof framing. Moreover, the foundation helps to keep the floors level, the basement dry, and, believe it or not, windows and doors operate more smoothly with a well maintained level foundation. Your foundation is also an anchor of sorts.
Maintaining your foundation is necessary to avoid structural issues that can ruin your home very slowly. The first and foremost requirement to maintaining your foundation is to correct any underlying moisture problems that your basement may be receiving from the exterior (See “Wet Basements”). Once you have diverted all outside water away from your foundation, the majority of your foundation maintenance is complete.
POURED CONCRETE FOUNDATION
Poured concrete is tough stuff, but even concrete will crack, chip and crumble. Eventually, nature has her way. New England temperature extremes make their presence known through damage to concrete structures. I recommend that you inspect your concrete and masonry walls and slabs for damage on a regular basis. Early spring is an excellent time to assess any damage that may have happened from our winter freeze/thaw cycles.
Cracks, chips and broken or flaking areas in concrete are not only unsightly; they can lead to further deterioration of the surface and it will allow moisture to seep if not properly maintained. The result is a costly replacement project as opposed to a simple repair once you notice any damages. A simple parge coat of lime based mortar over any spalled or chipped areas will alleviate worsening of your foundation’s condition.
If you notice any hairline cracks, simply monitor them for worsening. To monitor these cracks, I recommend that you get a small piece of glass and apply epoxy to both ends of the glass and place this glass over the crack so the epoxied ends sit on each side of the crack. Protect this glass from anyone accidently hitting it if possible. If you go back to this glass later and find it cracked, you’ve got a foundation that is still continuing to move. A structural engineer would be your best advice at this point. If you all of the sudden notice water stains at the foundation cracks, be sure to correct all outside drainage first “See Wet Basements”. After all exterior drainage is corrected and water still continues to seep into any cracks, you need to consider an epoxy injection that will definitely stop any future seepage at these cracks.
This type of stone foundation needs to be monitored on an annual basis. If your fieldstone foundation is not maintained over the years… bowing, bulging, shifting or settlement of your stone foundation may occur. If you find that any one these conditions have occurred, you should call in the services of an experienced Mason to make corrections to damaged areas immediately. However, if the stone surface is exposed, and they appear to be generally where the original builder placed them, you can probably handle the repairs and maintenance yourself. Determined do-it-yourselfers can perform much of the routine restoration and maintenance that will make their home’s foundation last for many years to come.
Most fieldstone foundations have, or had at some time, a thin mortar coating on the face of the stone. The purpose of this coating was to assist in holding the stones in place. This thin mortar coating will inevitably flake off from any moisture migration, revealing the surface of the stones. As this coating continues to erode, and exterior moisture continues to seep through this foundation, the mortar between the stones will begin to crumble and the soft, sandy mortar begins to slowly fall out of it’s cavities and onto the basement floor. It looks like a small pile of gray sand at the base of the foundation. When this occurs, tuck pointing is needed to refill the voids where the old mortar has fallen out. It’s very important that you or your mason scrape away or chip away the crumbling mortar (in between the stones) in order to establish a small cavity or keyway which can hold the new mortar that is being applied. Never apply new mortar over any old crumbling mortar, as this is a temporary fix and it will only last a couple years. All crumbling mortar must be removed in order for the newly applied surface to bond properly. While upgrading your field-stone foundation, only work on a section at a time. Do not remove the old mortar throughout the entire basement all at once. Complete all removal, tuck pointing and parging one section at a time.
To avoid annual tuck pointing, you should finish the foundation with a complete top coating of mortar. Be sure that the new mortar is lime based. This top coat does not have to look like a stone artisan’s creation: It merely has to serve the purpose of keeping the newly installed mortar in place. It’s sort of like applying a frosting to a cake. Of all the components of a building that need either restoration or maintenance, the area buried deep in the ground is often the most neglected. By taking these steps to keep the mortar in between those stones in tact, your foundation will last forever.
If your fieldstone foundation seeps water, do not attempt to perform the above repairs until you correct your exterior drainage. Once your drainage is properly in place, and your foundation continues to seep water, you need to invest in a B-Dry system. I’ve seen many of these systems in action, resulting in completely dry basements. I have never seen these systems fail so long as you continually maintain and test the sump pump and always have an additional sump pump on-hand, just in case the primary pump fails.
There aren’t many slab foundations in Ontario, but when there are slab foundations they are the most modern, and they can vary considerably from older ones that have no moisture barrier beneath them and any reinforcing steel within them to newer ones that have moisture barriers beneath them and adjustable reinforcing steel within them. This type is called a post-tension slab, but is often impossible to distinguish one slab type from another in which even the size and spacing of the bolts can vary, although most are concealed.
My inspection of slabs conforms to industry standards. I examine the visible portion of the stem walls on the exterior of the structure for any evidence of significant cracks or structural deformation. However, I do not move furniture or lift carpeting and padding to look for cracks, and we do not use any specialized tools or measuring devices to establish relative elevations or determine any degree of differential settling. Significantly, many slabs are built to move out of level, but the average person would not realize this until there is a difference of more than one inch in twenty feet, which most authorities describe as being tolerable.
Interestingly, many slabs are found to contain cracks when the carpet and padding are removed, but there is no absolute standard for evaluating them. However, those that are less than 1/8″ and which exhibit no significant vertical or horizontal displacement are not regarded as being structurally threatening. They typically result from common shrinkage, but can also be caused by a deficient mixture of concrete, deterioration through time, adverse soil conditions and poor drainage, and if they are not sealed they can allow moisture to enter your home, and particularly if your home is surcharged by a hill or a slope, or if downspouts discharge adjacent to the slab. However, in the absence of any major defects, I may not recommend that you consult with a structural engineer or a foundation contractor, but this should deter you from seeking the opinion of any such expert. Also, the condition of utility lines (drainage, water, gas, electric, cable) that might run in, under, or through walls within slab-on-grade foundations cannot be determined due to construction.
BRICKS AND BLOCKS
Bricks, at one time, were used extensively to construct foundations. Today, however, if a foundation doesn’t consist of concrete, it is probably constructed of concrete block. In either case, brick and block have one thing in common. They are both joined together using mortar, a combination of sand and cement.
Unfortunately, over time, the mortar tends to deteriorate. Cracked and deteriorating mortar joints are not only unsightly, they also diminish the integrity of the surface and can allow water to get behind the brick or block causing major damage. This can be avoided by tuck pointing the brick or block foundation, which means the removal by surface scraping (to establish a key way) and replacement of the cracked, crumbling or missing mortar. Monitor your bricks and blocks periodically and upgrade when deterioration is obvious. If the cracked or deteriorating mortar is extensive (an entire foundation wall), tuck-pointing is a project that is best left to a professional Mason.
BASEMENT MOISTURE AND HUMIDITY
All basements are subject to high humidity and moisture levels, especially between Spring and Autumn. Typically, basements are mostly below the ground level. Therefore, basement foundations and floors are in constant contact with damp soil. Moisture will typically transmit through these surfaces by way of capillary action, commonly referred to as moisture migration.
This condition is indeed expected and can be controlled by exercising some simple remedies. However, if low relative humidity and/or moisture content in the basement space is required for specific or special purposes, remedial action can be very expensive.
The following recommendations will assist to reduce high humidity and dampness levels in basements:
- Cold stroage rooms must be natrually ventilated either with an operating window or a wall vent.
- Install an exhaust fan in the basement bathroom or shower.
- Avoid storage of materials directly against unfinished foundations walls or unfinished basement floors.
- Too much storage of material in a basement, or overfilled closets, will impede air circulation.
- A small room fan could be operated to encourage proper air circulation.
- Ensure that all spaces in the basement are ventilated. Undercutting of closet doors, cabinet doors and installing wall grilles may be required in the storage areas.
- Seasonally disconnect your central humidifier (in April, if attached to your furnace).
- Position a dehumidifier in a central basement location and operate continuously.
- Open basement windows whenever possible to allow for a natural air change.
- Leave the furnace fan on continous operation in houses with a forced-air heating system. Ideally, return-air inlet grilles should be installed low on the wall in a central location.
How To Prevent Basement Problems
Many homeowners are not aware that basements require a certain amount of maintenance if they are to remain trouble free. Here is a list of items for outside and inside your basement that you should check twice a year – preferably in spring and again in fall.
Inside the basement maintenance checklist
Sump Pump: Make sure it pumps. Also, make sure that the water level is at least 8 inches below the top of the basement floor so the drain tiles drain properly. Poor drainage from the drail tile can result in plugged tile and leaks.
Palmer Valve: In some homes where the drain tiles meet the floor drain you will find a Palmer Valve. This is a valve -like door that only opens one way. It allows water from the drain tile in to the floor drain. Sometimes it can stick, causing water to back up through floor cracks and around the edges. Check to see that it is working freely or have your plumber do it.
Wall Cracks: All residential basements have some cracks which are perfectly normal and are a result of original settlement and/or shrinkage of construction materials. These cracks may have a tendency to open and close slightly with the changes in temperature and are no cause for alarm. However, any horizontal crack in a concrete block wall is a result of a wall’s inability to withstand external forces. Many of these walls require reinforcement that should be done by a professional.
Outside the basement maintenance checklist
Grading: If water runs towards your walls rather than away, it can wear out the original waterproofing, or create more pressure than the walls can take; causing cracks. So, in the spring and fall check around the entire perimeter of your home (especially behind the shrubbery) and fill in low spots with soil. Concrete pitched toward the walls should be re-leveled or replaced.
Gutters and Downspouts: Clean leaves out of the gutters and downspouts. Seal leaking joints. Extensions and splash blocks should carry water at least four feet away from the walls. Downspouts that empty into the underground cast iron receivers should be tested with a water hose to make sure they are not plugged or broken.
Window Wells: Clean all debris out of window wells. There should be 18″ of #1 washed stone in the bottom of each window well for drainage. If the original stone packed with dirt, dig it out and replace it. The edges of the wells should be tightly fitted to the walls and the ground around them raised so the rain and melting snow run away.
Sump Pump Discharge: If you have a sump pump pipe discharging on the ground make sure it carries the water far enough away from the walls. If it discharges below the ground, make sure connections don’t leak and are not in danger of freezing in cold weather.
Trees: Roots from nearby trees can creep through the ground in search of water and grow right in to drain tile or create undue pressure on the walls. Willow tree roots for instance can travel in the ground four times the width of it’s canopy. Consult an experienced landscaper or the County Agricultural agent when in doubt about the danger posed by trees or shrubs in your yard.
How to Choose a Basement Repair Contractor
Choosing a basement repair contractor is different than choosing almost any other kind of contractor because both the underlying causes and the real repairs are hidden by the ground, walls and floor. In most cases it will take some time before the quality of the repairs are tested. Therefore, this is very much a faith and trust business. You should check carefully on the experience, integrity and ability of the contractor.
Visit the contractor’s office. Sometimes it is no more than an answering service. For references, take names of previous customers at random from his file.
Ask to see a job in progress to evaluate the competence of the workmen and their equipment.
Resist all scare tactics. Repairs are seldom of an emergency nature.
Reliable contractors’ welcome careful investigations.