Structural Flaws

Getting to the heart of things.


Getting to the Heart of Structural Flaws:

The ad read, "Handy Man Special, minor structural repairs probable." I had long wanted to tackle a "fixer-upper." I had faith in my basic skills and felt this would be a good way to earn equity in a house. But I was worried. How could I tell if the place was structurally sound?

Well, I bought that house and fixed it, too. And along the way I found out how to tell if a house is sound.

Here is my recommended "10 minute EKG" for evaluating the foundation of any house you are considering for purchase. You won't become an expert on structural soundness, but it can help you avoid a lemon and know when to seek professional advice.

You'll need a strong flashlight and some basic understanding.

The foundation is the masonry that supports the house. Built into the ground, it supports the weight of the house and keeps the dirt out of your basement. Movement of any part of the masonry usually spells trouble and can be detected by cracks in the walls of the foundation. You can read some meaning into those cracks.

The foundation usually consists of two parts: the footing and the walls. The footing is a concrete pad about eight inches deep and usually 16 to 24 inches wide. The footing supports the walls, which may be masonry block or poured concrete. The deeper the basement , the thicker the walls must be to resist the pressure of the outside earth. (The concrete slab on the floor of most houses is not a structural component and almost always has some hairline cracks, which are usually caused by shrinkage. These can be safely ignored.) However, never ignore large or multiple cracks in any surface.

To begin your inspection, start in a basement corner and look down the wall surfaces. Make sure the walls are straight (in a flat plane, perpendicular to the floor and ceiling.) Inward bulges in the wall may mean the earth is shoving in and are signs of big trouble. Back off from the wall, walk alongside it, and examine it from top to bottom. Cracks or cracks that have been previously repaired should get close attention. Scan every wall and note what is outside each wall.

It is important to distinguish between the normal cracks found in foundations and those that indicate structural trouble. Don't worry about the house's early settlement (initial movement that usually occurs within the first two years of a house's construction) or very old cracks. Be more concerned with continuous movements, not one-time movement.

Diagonal cracks starting in the corners and progressively widening as they rise from the floor are very common. They often step along mortar joints in a roughly diagonal direction and often occur within the first two years of construction. The early movement and resulting hairline cracks usually occur because the footings are unevenly loaded and frequently rest in soils of somewhat differing bearing capacities. (Bearing capacity is the ability to support weight without sinking or compressing.) Small hairline cracks like these are usually safely ignored.

Watch out when you spot the following conditions: A diagonal crack that exhibits signs of recent movement especially if it occurs after initial settlement.

A large crack. (If your finger can fit in it, it is large.)

A long horizontal crack on an outside wall.

A vertical crack on any wall.

A slant or bulge on any wall.

Cracks large enough to admit you little finger are significant and are best examined be someone with experience. Other signs of recent movement are a crack that was filled with mortar and has reopened; or a crack in a recently painted wall with no paint within the crack.

A very common crack is a long horizontal one significant above the slab height. These cracks frequently occur a foot or two below the outside soil surface in a masonry-block foundation and are often caused by water that has collected against the masony, frozen, and then exerted inward pressure.

This usually occurs because the gutters and downspouts have failed to deliver runoff water far enough away from the foundation. Repairing the gutters and spout and increasing the grade (the slope of the soil away from the house) ordinarily will be sufficient to deal with the problem. But if the crack is more than 1'8 inch wide, "pinning" may be necessary. Pinning consists of inserting bars into the cores of the blocks and grouting (filling with concrete) around the bars. This greatly increases the tensile strength of the wall and often isn't very expensive.

Other common horizontal cracks can occur high up on a basement wall on the inside of the foundation wall where it touches the garage slab, that is the concrete that the car rests on in the driveway. When a garage slab (or any outside slab) settles, it can push the foundation wall. But as long as water isn't running down the driveway and getting under the slab there is probably no cause for concern. The force of tree roots can also produce large horizontal cracks and bulges. Remove the root and pin the wall as noted above.

Vertical cracks are usually found at the midpoint of walls; they can be uniform in width, or more commonly, can progressively widen as the crack rises from the floor. This usually means that the corners of that wall of the house are still settling. This is cause for concern.

Houses that are still settling usually call for "underpinning", a method of enlarging existing footings to better enable them to handle the weight they support. Houses resting over expansive soils may even require piers under their footings to transfer their weight to stable soil. These cures tend to be expensive and call for a professional evaluation.

Almost all structural problems are related to moisture in the soil. If movement is suspected in a house, poor drainage is the likely culprit. So it is particularly important that the drainage around homes be maintained. Houses on hillsides with deep basements sometimes get bulges in the uphill foundation wall. This is often due to poor drainage; the resulting saturated soil increases pressure against the wall. The wall could collapse.

If the gutter downspouts of a house empty at the corners of the house they can frequently saturate the soil, which lessens its bearing capacity. Improving the drainage to eliminate saturation is often sufficient to arrest ongoing movement.



Filling the gaps to save a bundle.


Filling the gaps to save a bundle:

Household air is always in transition. Conditioned inside air moves out and outside air moves in (requiring reconditioning.) The rate at which air does this is called the infiltration rate. A very tight house will see its total volume of air exchanged about once an hour while a very loose one will lose its heated air at three times that rate. The difference in utility bills for the two houses would be huge. Most houses have a handfull of places or areas which account for the bulk of these losses. Fill these gaps and you will substantially lower you energy costs.

Minor Miracles With Cheap Materials: You will need several rolls of fiberglass blanket insulation (3 1/2 inch thickness is fine), some rope caulk (a type of caulk that comes threaded on a cardboard backer like fat shoelaces), duct tape, weatherstripping and a pair of work gloves.

WARNING: It Can Be Overdone: An excessively tight house can develop condensation problems. ALL houses should have kitchen and bath power exhaust fans and should have vents through the attic spaces. About the only old houses that develop condensation problems through tighten up measures are solid masonry houses which have their old drafty windows upgraded to very tight fitting new ones and have no exhaust fans. Unusually tight houses may require the aid of an "Air-to-Air Heat Exchanger," a device which efficiently transfers heat energy from outgoing inside air to incoming outside air while making the exchange.

Floors: If you ever refinish flooring, consider caulking between the baseboard and the floor prior to installing new shoe molding. Stuff pieces of fiberglass insulatin around ducts and pipes penetrating floors. Use gloves since the fiberglass can "pin prick" you.

Attics: Most attics are incompletely insulated so that heat can readily escape through uninsulated areas. Examine the attic floor around a fireplace chimney, above bathrooms and closets, over kitchens and stairs, and the top of whole house exhaust fans. Lay fiberglass blankets over uncovered spaces. Construct a shell cover for a whole house exhaust fan from cardboard boxes stapled together and then staple the insulation to the back of the box. Do the same for attic pull down stairs an staple insulation to the tops of attic access hatches.

Heating Equipment: If your gas or oil fired furnace or boiler is located within the heated living space of the house it uses the already heated air to combust its fuel. If it is in a small room with a vent through a door, consider taping over the vent, sealing around the door with weatherstripping and ducting outside air into the room. Many times you can run a duct up into the attic. Consult local building authorities for the property size duct.

If the equipment is installed in a larger space, you might consider installing a "flue damper" in the exhaust flue of the appliance. These devices restrict the flue opening when the device is not running. This can provide big savings since open flues are direct pathways for inside air to exit the house. Handy amateurs should limit themselves to installing thermally activated flue dampers on gas appliances only. Leave electrically operated dampers and dampers on oil burning equipment to professionals.

Ductwork: Seal the joints of uninsulated return air ductwork through uninsulated attics and crawl spaces with duct tape. These returns pull a partial vacuum and cold air will be drawn into them from these spaces. Consider wrapping them with insulation.

Dampers: Look up inside the firebox with a flashlight to check your fireplace damper. It should seal tightly all around its edged. Clean out any debris or mortar that prevents a tight fit. If you don't have a glass fire screen, be sure to keep the damper closed when the fireplace isn't being used. Check bathroom exhaust fan flappers by feeling around the fan for drafts on cold windy days. Remove the ceiling register and drop the fan to unstick a drafty damper. Pivoting dampers in kitchen exhaust fan ducts emptying into attic spaces often stick open due to grease accumulations. Clean them with a suitable cleaning solution.  Clean lint from the flapper on the dryer exhaust duct to make sure it closes properly.

Basements and Crawl Spaces: Wood frame houses will have floor joists resting on a "sill plate" mounted to the foundation walls. Caulk the space between the bottom of the sill plate and the top of the foundation. Caulk around electrical and gas pipe entrances through the foundation. Stuff fiberglass blanket insulation between joist ends against the outside walls. Make sure any gaps at the floor above are blocked off. Tape around steel framed (hopper type) basement windows. Stuff fiberglass into cantilevered floor cavities that overhang foundation walls; fill the entire cavity.

Doors: Weatherstrip around the top and sides of doors. Use a compressible weather stripping that tacks to the door jambs. Make sure the threshold is a tight fit at the bottom of all doors. Take the threshold up and caulk under it if necessary. A "sweep" attached to the inside bottom face of a door will aid a poor sealing threshold. This operates like a thin brush connecting the bottom of the door to the floors.

Windows: Install felt to take up space on window parts that fit poorly. (Make certain that the locks work to pull the sashes together.) Use rope caulking pressed into cracks around window sashes that cannot be made to fit tightly. (Rope caulking is the most practical answer to tightening steel casement windows.) Tack telt strips to the top of the upper sash and the bottom of the lower sash for loosely fitted double hung (the kind that move up and down) wood windows.

Switches and Plugs: Install foam gaskets behind switch and plug face plates on outside walls.

Ceiling Openings: Lighting fixtures, duct registers, and other openings through ceilings should be sealed around to prevent falling air drafts. (WARNING: Most lighting fixtures that project through a ceiling into insulated space require three inches of space to any insulation to prevent heat buildup and fire. This automatically sets up holes through your insulation blanket and accounts for cold drafts through the lighting fixture itself.) Fix this with a gasket under the rim of the lens cover or change the lighting fixture. Safe "Hi Hat" light fixtures that can be covered with insulation are label IC (Insulation Contact) and are available from lighting distributors. Older lights can be fitted with cool running fluorescent bulbs.

NOTE: Blowers doors can be used to check for high infiltration rates and duct blasters can be used to check for leaky duct work. This type of work is often available from companies specializing in energy conservation.


Homeowner Tips

Mold Concerns


Minimizing the Miseries of Mold and Mildew:

You might smell a musty odor when you walk into your house or maybe just when you go into the basement. You might sneeze, you might not. Maybe you're allergic to mildew or mold spores, and maybe you're not, but chances are you really don't know. While some medical experts say that about 30 percent of the general population may be allergic to mold and/or mildew, they note that most in that group of people who are only mildly allergic, probably ignore the symptoms.

Whether or not you are allergic, mildly or otherwise, it's easy to keep minor mold and mildew under control. So for your own comfort, perhaps, and for the convenience of potentially allergic guest, here's what you should know.

Spores and Dampness: Think of mildew and mold spores as microscopic seedlings floating in the air. They are everywhere in trace concentrations; the problems start when the concentrations increase. When airborne spores make contact with damp or moist surfaces, they multiply rapidly. While you can't eliminate the spores, you can do a lot, with proper ventilation and humidity control, to eliminate their breeding grounds and lower their concentration.

Humidity refers to moisture in air, the higher the air temperature, the more moisture air can hold. The amount of moisture the air is actually holding relative to what it is able to hold is called relative humidity. If air, at any given temperature, is holding all the moisture it can, the relative humidity is said to be 100 percent.

Wall: When an air mass at 100 percent relative humidity encounters a colder surface, a glass filled with iced tea for example, some of the air will cool. Since the cooled air can hold less moisture than it could when it was warm, some of the moisture from the air will condense, probably on the outside of the glass.

The same effect takes place when warm air comes in contact with cooler walls, something that happens in various seasons at various times of the day on the inside and outside of all buildings. Inside it often occurs when heated air comes into contact with cool interior walls, especially in uninsulated basements (finished or unfinished.) Outside this can happen when the air meets the shady part of the house in the evening, when the air itself is cooling and beginning to lose some of its moisture; encountering a cooler surface accelerates the condensation. In both cases, airborne spores are deposited on the damp surface and rapidly multiply.

NOTE: Operating dehumidifiers in basements is a good idea in the summer. Spreading chlorinate lime crystals over a concrete floor can absorb moisture and kill mildew as well.

Sometimes mildew will form on a foundation wall behind a finished wall. If there is a return grill in the basement it can cause a negative pressure on the basement area and pull mildew spores into the living space air. Special chemical fogging can sometimes be used to kill the mildew behind the walls. This is a job for a professional.

Crawl spaces: Homes with crawl spaces rather than full basements often suffer from very damp conditions, frequently unobserved for years. The problem here is a basic one, usually caused by water seepage due to poor landscape drainage and leaking pipes, resulting in a closed area with high humidity and lots of mildew and mold.

To make matters worse, the humid air tends to rise, carrying spores into the spaces above.

Heating and cooling systems: Forced-air heating systems work by recycling household air over hot metal. Simultaneously, they can raise the spore concentration throughout the house in several ways.

Forced-air systems often are fitted with humidifiers designed to add moisture for increased comfort during the winter. Many humidifiers operate by passing a sponge or metal discs through troughs of water that are almost always spore generators. Forced-air systems also may be fitted with air conditioning coils above the furnace. The coils 'perspire' and dripp moisture into a drain. If the system is poorly filtered, dust can collect on the wet coils and provide a perfect environment for spore growth.

Some forced-air systems in homes built on slabs have ducts laid under the slabs. These ducts are good spore breeding grounds because humid summer air can enter and condense on the cooled interiors. In addition, poor drainage around a house often will allow some water to seep into the ducts. Return ducts through damp crawl spaces act like vacuum cleaners sucking up spores,

SPECIAL NOTE: Some rarely used forced air systems actually utilized sealed crawlspaces for delivery of the air. Air was pressured into the space and then exited via grills cut into the flooring system. No ducting was utilized. This type of system is highly likely to contribute to mildew and radon problems.

Closets: Closets on outside walls often have mildew or mold growing in them because there isn't enough air movement to ventilate the space properly.

Attics: Moisture tends to rise in houses, and if the attic is insufficiently ventilated it can condense on the cold underside of the roof.

Basement walls should be insulated with a plastic vapor barrier stretched against the foundation.

Dehumidifiers should be run in the summer with the windows closed.

Clothes dryers should be vented to the outside of the house.

Steamy bathrooms can be fitted with exhaust fans.

Mildew on walls can be sponged with a solution made from one quart of chlorine bleach, one gallon of water, one-third cup liquid household detergent and one-third cup of trisodium phosphate. This solution may bleach out some colors, so try it first on a small, inconspicuous spot. (Because chlorine and ammonia give off a poisonous gas when they are combined, be sure the household detergent does no contain ammonia. Never mix chlorine and ammonia.)

Crawl spaces should be kept dry. Make certain the grading against the foundation works to keep water away. Stretch a 6-mil polyethylene (plastic) vapor barrier over any dirt. Vents through the foundation walls should be left open. Fungicides can be applied to mildewed of molding flooring.

Furnaces should be kept very clean (include the inside coil in your air conditioning maintenance contract); ducts that run through crawl spaces should be sealed and insulated; and trough-type humidifiers should be avoided.

Closets should not be stuffed with clothing. Allow space for air circulation and consider installing a vent in the door.

Never close attic vents for the winter and make sure they are not blocked by siding. If bath or kitchen exhaust vents open into the attic, extend those ducts directly to outside vents. Problem attics can be fitted with additional vents.

Caveat Emptor: When buying a house, persons with known allergies to mold and mildew should avoid those with basements or crawl spaces; if that is not possible, they should be certain that these spaces are bone dry. Also, avoid houses with slab duct systems and houses that are heavily shaded and surrounded by trees.

CAUTION: This primer is an over simplification to assist quick understanding. MIldew and mold problems can be difficult to control and may require professional help by a heating and air conditioning specialist  or mold eradication-environmental specialist.