Renovation & Design
Renovation & Design
Heating ducts in concrete may present unique challenge
Question: I am hoping you can tell me how a repair can be made to the heat vents which are laid into the cement slab. I think this winter my house shifted in such a way as to crack a vent, which filled with water recently, after all this moisture. Needless to say, I was in shock, as I have had this house for 25 years and never had such a thing happen. Is this repairable? Thank you, Sandy Brow Thiessen.
Answer: Specialized repairs to heating ducts, especially those located in hard-to-access areas, may only be attempted by very experienced HVAC contractors. There may be several different methods for this repair, and only those with many years of direct experience will be the ones able to answer this question for you.
Repairing heating ducts embedded within a concrete floor slab may be a unique challenge, especially in our area. While there are a few older neighbourhoods where slab-on-grade homes were built, most houses have full basements or crawlspaces. The reason that slab homes are not common is due to our harsh winter and soil conditions. Because slab homes are literally built with the foundation on, or just above, the grade they are more subject to seasonal movement. Because of our extremely cold weather, our expansive clay soil may significantly swell in the spring, when the weather warms and the frozen ground thaws. This may vary from year to year, depending on the severity of the winter and the soil moisture content.
With a full basement concrete foundation, the footing support for the house is typically one to two metres below grade. While the soil outside the home may freeze this deep in a very cold winter, in some milder years it may not. The deeper the footing is, the less chance it will be affected by frost-related heaving, as the frozen moisture in the ground expands. Houses built right on grade, like yours, will have little protection from this movement. Also, if your grading is low around the house, moisture from rain and snowmelt will easily penetrate the soil underneath the perimeter of the home. The wetter the soil under this area, the more chances of seasonal movement of the home.
As you have recently experienced, excessive moisture from very snowy winters and heavy rainstorms may seep further underneath the concrete slab. While this may also be a major problem for homes with basements, they are equipped with a floor drain, and often a sump, to drain away any basement water. You probably don’t have any such mechanism in place to prevent the accumulation of water under the slab foundation. Unfortunately, embedding the heating ducts in the slab may have been necessary to install forced-air heat in our climate, but it can have very negative consequences.
While I have seen these older ducts with significant corrosion near the boots below the floor registers, specialized equipment would be required to fully investigate the condition of the entire duct system. This would likely begin with a scope of the ducts with a snake camera, often employed by rooter technicians and plumbers to inspect potentially damaged plumbing drain pipes. I suspect that your ducts may already have had some damage, simply from years of contact with the cold concrete floor slab and the soil beneath. However, most of this deterioration would have been hidden. If there are any areas that have major rust, holes, or damage, replacement would definitely be in order. There may be the possibility of installing a non-metallic liner inside the existing ducts, but I have no personal experience with such a system.
The main concern I would have with the recent flooding of your heating ducts, and possible pre-existing conditions, would be mold and other contaminants inside the ducts. If the water remains inside the ducts for more than a very short time, mold would likely begin to grow. It will use any dust, dirt, mouse droppings, or soil inside the ducts as a food source for the mold. By wetting this material, conditions would be ideal to support mold growth, with the byproducts able to circulate through your home via the HVAC system. This could be a significant health concern should anyone in your home be sensitive or allergic to molds. For that reason, I would immediately try manually removing the water, with a shop vac, utility pump, old towels, or any other method available. Once it is almost all gone, running your furnace blower continuously, and renting commercial dehumidifiers, will help dry the ducts further.
As far as removal and replacement of the ducts, that would present an extremely difficult challenge. The only way that would likely be possible would be by cutting the concrete floor slab, in several areas, and chopping out those sections. After removal, the damaged ducts could be pulled out and eventually replaced, once no more moisture was present under the area. After that, the openings could be filled in with new concrete, to patch the slab. This would have to be completed in a manner that would not compromise the structural integrity of the slab, which is the foundation of the house. Removal of too much concrete could subject the home to even more movement than usual. Hiring a structural engineer, prior to any work, would be a prudent choice to provide a plan for safe removal of any portions of the floor.
After getting the water out of the flooded heating ducts embedded in your home’s concrete floor slab, proper planning and experience by a professional structural engineer and very experienced, licensed HVAC contractor will be required. Only those professionals will be able to fully answer your questions, and devise a method for this extremely difficult repair.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and a Registered Home Inspector (RHI)(cahpi.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.
trainedeye@iname.com
Renovation & Design
Lemon juice and baking soda make dishes sparkle
Question: I own white dishes, and my bowls are stained on the insides from frozen cherries because I put them into the bowls until they are defrosted. How can I safely remove the cherry stains without using toxic chemicals? Marsha
Answer: Some people have great results by scrubbing each bowl with a scrubby pad dipped in lemon juice and baking soda. But when the stain is stubborn try the following recipe: In a large pot, combine three cups vinegar, four cups water and two tablespoons of citric acid. Heat, but do not bring to a boil. Set each bowl in the hot mixture for five minutes (the water must cover the dish). Once dry, your dishes should look brand new.
Question: What is the safest method for cleaning stuffed animals? I have a collection and some teddy bears are more than 10 years old. Thank you, Dana
Answer: Vacuuming teddy bears is the least risky way to clean them. However, wiping with a damp white cloth is one of the simplest and most effective ways to clean your teddy bears. For stubborn dirt, grime and odours you will have to resort to a stronger cleaning technique. Check the care label on your bear. To dry your teddy bear, never use the machine dryer. A better way to dry the teddy bear is with a hair dryer. If your teddy bear is an antique, avoid washing or cleaning the bear yourself. There are special establishments who specialize in restoring teddy bears. Another option is to place your teddy bears in a garbage bag with a half cup of baking soda. Shake to freshen. This will remove dust and stale odours, but it will not remove stains. To remove stains, use the wet cloth technique stated above.
Question: What is a safe solution for removing rust on my bike? A.J.
Answer: Make a paste of 50/50 baking soda and water. Apply the solution to the rust. Leave for about 15 minutes and then scrub. If the rust has eaten through several layers, you will need to sand and repaint.
Handy hints
I use make-up pads that come in a plastic “sleeve.” When I was coming towards the centre of the sleeve, I was having some difficulty grabbing the pad so, I came up with a solution to my problem, by pushing the pads towards the top of the sleeve/tube and twisting it and then tying it with a twist tie. Now the pads are once again at the top of the sleeve/tube, and easy to get at. I hope you will be able to understand my instructions. Kind regards, Anne Marie
Next time you make fajitas; add cooked pork, peppers, onions and seasoning to your baking pan. Next cook powdered onion soup and water on the stove. Thicken soup with cornstarch (the way that you would gravy). Add this to the fajita pan for great flavour and texture. Bake to heat. — Mary
To remove the peel from garlic cloves. I have the following tip: microwave a clove or two on high for about five seconds, then cut off the end and the peel will just slide off. — Joel
The easiest way to clean your oven. Pour one cup of vinegar onto the bottom floor of your oven. Sprinkle on a half cup baking soda. Leave overnight, wipe away in the morning. — Jessie
Note: Every user assumes all risks of injury or damage resulting from the implementation of any suggestions in this column. Test all products on an inconspicuous area first.
Have a great suggestion or tip? Send an email. Reena Nerbas is a popular motivational presenter for large and small groups; check out her website: reena.ca.
info@reena.ca
Renovation & Design
Regrading is best bet to prevent pooling water
Question: I’ve been reading your column in the Free Press for a while now and appreciate all your advice and guidance. I have a bit of a similar situation to that addressed in an older article you wrote, about a void under stairs. I have water pooling under these concrete stairs, which came in after all the wet weather. Now the water is going across my foundation and finding its way to a couple of window wells, which are plugged, of course. It is leaking in there and from my chimney clean out, as well.
Is using mudjack material to fill the void a good alternative to shovelling in quarter down?
I appreciate any insight, as Google doesn’t offer any solutions, Greg Fast
Answer: Filling in eroded or shrunken soil under older concrete steps should work to prevent foundation seepage, no matter what is used for the fill. As long as the top of the fill is well above the surrounding grade it should prevent water from pooling in that area and sitting up against the concrete foundation wall.
Having written many times about the need for proper grading to prevent moisture intrusion into a foundation, I am not sure what exact recommendations I proposed in the noted column. I am sure that it was suggested that filling in any depressions adjacent to that area, especially underneath stairs, was critical. Any voids under older concrete stairs, porches, patios, or additions are particularly important because they are typically hidden from view. While it may be easy to see standing water, from a heavy rain or melted snow, collecting in uncovered areas, the opposite is true in these locations. Moisture may collect and remain in large amounts in any hidden voids, and can take a long time to disappear, due to the lack of airflow for quick evaporation. Any water sitting against an older concrete foundation wall is likely to find its way through.
Preventing pooling water, and oversaturated soil, in any location adjacent to your home may be accomplished by simple regrading. Building up the grade, so that a gentle slope is created away from the foundation, is the trick. Because water will flow to low areas, either through or above saturated soil, regrading is critical. The opposite is also true, that water will not collect in higher locations, especially if there are no impediments to good drainage. The area under your stairs will have neither of these positive qualities, so upgrading will be required to prevent your problem from reoccurring.
To access that hidden area, partial excavation outside the stairs is likely the initial step. Digging a small trench beside the stairs, large enough to look underneath, will give you a good idea how bad the issue is. Shining a flashlight, or trouble light, into the cavity will help determine how much lower the soil is than the surrounding area. Once that is known, measurements can be made to figure out how much fill will be required to correct the situation. Enlarging the trench will likely be required, to allow better access for shovelling in material into the small cavity. As you have stated, granular fill is easier than soil to keep in place, so quarter down, pea gravel, sand, or mixed gravel is often the choice for this job. While soil of similar composition to the surrounding area may be a better choice, it can be difficult to obtain and manually shovel in our local clay-based soil into that space.
Your alternative of filling the void under your front steps with the same material used for mudjacking may be a good option, but will likely be much more costly. That specialized expanding soil can be fairly expensive to produce and pump under the stairs. While it may give you a superior product, which should be resistant to shrinkage and moisture absorption, it comes at a cost. The main benefit would be that you could hire a company to complete the entire installation. That would save you a significant amount of hard labour. If you are planning on hiring a contractor or landscaper to do the job, anyway, the additional cost of the mudjacking slurry may be the only difference. The other concern would be any possible disruption to the foundation, stairs, or surrounding components, due to the strength of that material. Since it is used to lift concrete slabs and other heavy components, care must be taken not to overfill the void and cause additional pressure, or physical damage, to any of the items noted.
The final areas to address are the window wells, chimney clean-outs, and other locations where the seepage is occurring. Filling in under your front steps may help prevent this from happening, but may not be the complete cure. Digging down to seal the old chimney base under ground will likely be needed to prevent further leaking in that location. Also, lifting up and securing the window wells to the foundation, if they have settled, as well as regrading inside and around them may also be a requirement. Shovelling built up snow away from the foundation next winter and spring may also help stop next year’s water infiltration.
Hiring a contractor to pump in expanding clay into the void under your stairs may be a viable, but costly, solution to your moisture issue. Especially if it is done in conjunction with other regrading and water-proofing improvements at the window wells and chimney. Otherwise, any fill that will eliminate the void and remain well above the grade outside the stairs should also help minimize future seepage.
Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and a Registered Home Inspector (RHI)(cahpi.ca). Questions can be emailed to the address below. Ari can be reached at 204-291-5358 or check out his website at trainedeye.ca.
trainedeye@iname.com
