Mold builds in an off-grid house

Q.  I own a house which is not served by power line electricity and has been vacant for some years. When I visit once monthly to check it, I turn on the gasoline  generator to run dehumidifiers to curtail the basement moisture build up. The generator will run until it is out of gas.

Mold on unfinished wood
Mold on unfinished wood

The extreme moisture has affected the house adversely. The doors are untreated wood, which have become hosts to an unsightly orange mold covering all surfaces. I could haul water to the house to wash the doors with a half and half vinegar solution, if you advise it.  What do you recommend to clean mold on the bare wood, which is old and stripped of all old finishes? Would you use the same treatment for painted wood?

I used Lysol or Clorox Wipes to wipe the grey mildew from the painted window and door frames, wiping them dry with paper towels. I do not want to add any moisture to the environment. I used Liquid Gold on some stained, not painted, closet doors. The windows are now slightly cracked to allow cooler air to circulate. Do you know of any kind of battery-operated fan that would be safe to use for several weeks between visits? I do have access to propane, if that has more possibility.

A.    Molds have gotten very aggressive in the last few decades. They affect the health of many people and, even if you are not allergic to them to the extent that you become ill, there is still long-term risk to your health.
You can try to remove as much of the mold as possible by wiping the affected areas with a solution of equal parts fresh Clorox bleach and water without rinsing.

But be aware that many mold varieties cannot be completely removed from porous materials like wood or gypsum board, and these materials may have to be replaced or treated more rigorously. I once did a forensic inspection of a house that had some very serious mold problems, and it had to be torn down.

It sounds to me, if the infestation is serious, that you might be wise to have an environmental engineer check your house out and recommend the best treatment.

Heat may be the solution in winter, but of course you’ll need an appliance that does not require electricity to function. Off-the-grid houses generally need to be lived in regularly.

An alternative to dehumidifier?

Q.    We live in a house that is essentially built into the side of a hill and as a by-product of this our basement always requires dehumidification. At a recent street fair I was exposed to a product called Humidex. The product seems to work like a large exhaust fan sucking the cold moist air that is at the bottom of the basement floor to the outside via a vent.

I wonder if you have any experience with this product or if you can offer us some ideas on how to make our basement more usable without the expense of a dehumidifier. The Humidex product boasts many claims which I could not substantiate with any Internet search.

A.    Neither could I substantiate their claim through their website. Nowhere did I find how the make-up air comes from.

A typical dehumidifier, still best for drying the air in a basement

Humidex claims that while the unit exhaust the “dirty, polluted” air from the basement, this dirty air is replaced with clean air. How? Sucking a lot of air from the basement floor to the outside will require that the negative pressure created be equalized. That means that the make-up air will either come from outdoors or get down to the basement through the basement or upstairs windows in warm weather when they are open. That make-up air from outside will be warm and moist, and will be brought into a basement that is kept cooler because it is underground, which compounds the problem. It could lead to condensation on the floor and on the lower parts of the walls.

Since it is not clear whether the unit has an intake as well as an exhaust, I called them and asked the question. The answer is what I suspected: the make up air comes from upstairs through grilles installed in the floor. They claim that the system works very well, that they have sold many units over 26 years with a money-back guaranty.

But of much greater concern is that, if the Humidex does not provide make-up air through the unit, as an air-to-air heat exchanger does, and if the house is reasonably tight and the windows are closed (like in the winter time), the make-up air is very likely to come as a back-draft through chimneys, including the heating appliances – a serious safety problem during the heating season since it will pull into the house the combustion gases that contain carbon monoxide!

Asked that question, the sales person answered that there are enough leaks in a house to provide the make-up air. Knowing that air, like water, moves through the easiest paths, their answer does not satisfy me because the closest source of make-up air is likely to be from the furnace or boiler located in the basement as well. The sales person insists that this is not the case.

At this point, it is up to each prospective purchaser to decide whether or not to buy. I would not for myself.

Refinishing an old softwood floor

Q.  I have an old farmhouse that I’m slowly redoing. After removing 3 layers of Lauan and Formica on the kitchen floor, I found a softwood floor set interestingly diagonally to the walls. I would like to sand and finish this floor.

Softwood flooring
Unfinished wide-board flooring

I would use polyurethane on it if it was a hardwood but I’m afraid if I finish it that way and something is dropped on it, (silverware etc.) It would chip the polyurethane and eventually look bad. Do you know of a better finish I could use?  Would a boat-building epoxy be a good choice or would it crack between the floorboards? Is there an epoxy made that is non-yellowing?

A.    Formica on the kitchen floor? That’s a new one on me.

You may be down to the subfloor. Before the advent of plywood and particle board, all sheathing on floors and walls was installed diagonally to prevent them from wracking.

If the subflooring is in good enough shape to be used as the finish floor, go ahead and use polyurethane. It’s OK on soft wood. I used it on my pine floors nearly 30 years ago. An experienced paint store person can tell you which varnish they recommend that would not yellow.

The traffic areas will have to be re-coated every few years, but that also goes for hardwood floors. Softwood floors are more prone to denting from furniture, etc., but that’s part of their charm. And I don’t think any finish would prevent denting.

Grass dies in patches of lawn

Q.  Over the years, you have provided me with many useful gardening hints. Here is my question and I hope you can help me.

Lawn with bare patches
Lawn with bare patches

I have several large patches of bare ground as a result of putting in drainage pipes in my lawn. I have rototilled the areas, raked up and removed all the weeds and rocks, put in Scott’s grass seeds, plus top soil and fertilizer, and watered throughout the spring and summer months.

All of the areas have nice shade from our trees. In some areas, I have done this three years in a row in the spring. The grass grows beautifully but sometime in mid-July to August, in all these areas, the grass starts dying and turns brown. Meanwhile, in adjacent areas of lawn, where there was no construction damage, the grass is still very green and alive.

As I mentioned, this has happened three years in a row. Every spring, I go through the process to put down new grass seeds because the entire area is bare and covered with weeds. Can you explain to me why the grass dies in August? Yes I know August is very dry, but the rest of my lawn is fine. Why doesn’t the grass put down deep enough roots after three years?

A.    There may be a problem with the chemical composition of the soil in the affected areas that affects grass.

I have a similar experience in a small area where I grow great rhubarb, but cannot grow radishes and other vegetables. A soil test was done and provided me with a list of the needed nutrients.

Call the extension service of your local university for advice on having the soil tested, followed by recommendations on treatment.

Cleaning algae from roof

Q.  This past year, we noticed black markings coming down the roof. Would you have any idea what is causing that, and will a power-washer clean it up? I’ve noticed several homes with shingles on their roofs with the same black markings. Do you have a solution?

Algae on Roof
Algae on Roof

A   Do not use a power-washer to clean roof shingles; it could dislodge the mineral granules that protect the shingles from UV damage. The black streaks are caused by a type of algae that grows on the mineral granules of the asphalt shingles when they do not dry fast enough after rain or after snow has melted off the roof.

There are several ways to remove algae. You can buy special solutions that are sprayed on the roof; you can have the cleaning done by firms that specialize in cleaning roofs, or you can do it yourself. If that is your choice, spray the shingles with a solution of equal parts fresh Clorox bleach and water. Use a plastic garden sprayer and apply the solution on a windless day at the rate of 1 gallon per 50 square feet of roof. The purpose is not to overspray and have the solution run off the roof for a long time.

Zinc Roof Strips
Zinc strips to control algae on roof

Wear rubber gloves and old clothing, as well as eye protection. Spray the solution from a ladder, as it is dangerous to walk on a roof, which may void any warranty left on the shingles.

If you have metal gutters, run water in them while applying the solution because it is corrosive. Soak all vegetation below the roof before spraying, cover it with plastic and rinse it thoroughly when you are done. Make sure there is no longer any solution dripping from the roof. It will take several weeks for you to notice any results.

Installing special zinc or copper strips at the ridge (or replacing an existing ridge vent with one specially made for this purpose) should prevent recurrence.

Green mildew on vinyl siding

Mildew on Vinyl Siding
Mildew on Vinyl Siding

Q.  I have green mildew on my vinyl siding. I used a 2200 PSI power-washer and was not able to remove all of the mildew. Is there a solution I can use to get the rest off without damaging the vinyl siding or do you have any other suggestions?

A.  I assume that you used a weak mixture or didn’t use bleach at all in your power-washer. Power-washing any mildewed surface without a strong bleach solution may remove some surface pollutants but it will not remove the mildew. If the mildew is found on small and easily accessible areas, you will have more success if you do it by hand because it is not easy to have the right concentration of bleach mixed with the water going through a pressure washer.

Wear heavy rubber gloves, mix fresh Clorox bleach and water in equal quantities in a 5-gallon plastic pail, and apply the solution with a soft bristle brush so as not to scratch the siding. If you add a cup of TSP or TSPPF detergent (buy in hardware stores) per gallon of the solution, you will also remove any other stubborn stains that plain water from the pressure washer didn’t get. If you only use a bleach solution, do not rinse it. But if you use detergent, you will need to rinse the treated areas.

Be sure that you cover vegetation with plastic after soaking it before and after the washing.

Pink (or green) rings in toilet

Toilet Ring
Toilet Ring

Q.  I recall a column that talked about pink rings in toilet bowls and a potential problem with acidic water eating away at my pipes. I wondered if you had an opinion on what the acceptable range for tap water pH should be. I have made some inquiries and am hearing that 6.5 to 8.5 is an acceptable range. Should I invest in a neutralizer if my pH is below 6.5 or does it need to be less than that to justify the expense?

A.  The ideal and neutral pH is 7. A pH of 6.5 is quite acidic. The fact that you have pink rings in your toilet (usually the rings are more greenish, although another reader recently described them as blue) seems to indicate that you need to have your water checked by a water specialist.

Bubbles appear when toilet is flushed

Q.    Can you tell me why our first floor toilet emits a bubble each time we flush? We are on a slab with a septic system. The vent is not blocked. We are elderly in need of help.

A.    This is usually an indication of a venting problem. If this happens only in winter, it may be that the vent stack through the roof has too small a diameter and ices up. If it happens year around, then the venting problem is different. Does it bother you so much that you can’t live with it? If so, consider having an experienced licensed plumber check it out.