Q. I have wall-to-wall carpet with scatter rugs on top. My problem is even though I have tried carpet tape and pads to keep them from moving, the rugs do not stay in place. I also have a 5-by-8-foot carpet under my coffee table that keeps buckling.

Any suggestions about how to keep it lying flat? There is wall-to-wall carpet under the 5-by-8 also.

A. Neither carpet tape nor pads under scatter rugs will prevent them from creeping and buckling because you have a foam pad and/or a high-pile carpet. Either one or both will cause scatter rugs to move and buckle.

The only way to have scatter rugs remain in place is if they are laid down on top of a low-pile carpet over a fiber pad. With this combination, scatter rugs do not need anything under them.

Q. My mother-in-law is moving from her house, which has a septic system, into an apartment. We have no idea when the septic system was last serviced. I have noticed that the toilet is sluggish.

We have public sewage at our house, so I am not sure how a septic system works. Could you explain how it works and discuss what some of the problems might be?

The buyer would want a dye test for sure.

A. A septic system includes a concrete or plastic septic tank set outside the house. Its partially treated contents flow into a distribution box that distributes them to a leach field by means of several drainpipes. These drain pipes are set on top of individual trenches or a single larger trench filled with crushed stones.

The effluent percolates through the stones and the trenches’ walls and bottoms into the native soil, where the soil’s bacteria take care of all the nefarious components of the effluent and return clean water to the water table.

Problems in the system can develop when the bottoms and sides of the trenches become clogged and can no longer absorb the effluent. This will cause a back flow that will surface onto the lawn and which can back up into the lowest fixture in the house.

A sluggish toilet may simply indicate that there is some obstruction in the waste line that may be easily removed with the use of a plunger, or it may require the use of a snake.

The rim holes and the jet hole in the toilet may also need cleaning. Consider having a licensed plumber check all the possibilities so that the plumbing system will function at its peak before a house inspection takes place.

It is always better to have any and all potential items that may cause a delay, or difficult negotiations, taken care of before an inspection. This is why I generally recommend that sellers be proactive and have a certified home inspector perform a pre-sale inspection. The inspector’s report can then be presented to the prospective buyers and make the sale a lot easier.

Q. I am 86 years old and have a problem, and I am not on the net. I have what appear to be wild

strawberries in some spots in my front yard and backyard. They are coming from my neighbors’ yard and they won’t do anything about it. They only care that their lawn is green.

I’ve spent nearly $1,000 on dirt and the best grass seeds. Any hints would be greatly appreciated.

A. Some people actually like wild strawberries and use them as ground cover. Wild strawberries send shoots over wide areas and are very difficult to eradicate.

The best information I can give you is to quote from Nikki Phipps, author of many gardening books and columns:

“Spot treatments of wild strawberry herbicide are probably one of the most effective means of getting rid of wild strawberry patches. In fact, most broad-leaved weed killers work well on wild strawberries. They can usually knock out weeds without harming grass, making them a good option for lawns. As with any type of chemical control, these must be used with care, so read and follow all label instructions.

“The most effective types for use on wild strawberries generally contain three different herbicides (called three-way herbicides), such as Trimec. Keep in mind that wild strawberry herbicide is not always foolproof. Plants are prone to re-emergence, so additional applications may be necessary.

“Broad-leaved herbicides should not be applied during hot weather. Since wild strawberry weeds (and other broad-leaved types) are more susceptible to herbicides when they are actively growing, it is better to wait until temperatures cool off — with mid-spring or early fall applications being the best time.

Q. I have a long concrete driveway that is about 35 years old and in good condition. I would like to pressure wash it, then seal it. What would you recommend I use for the sealer? What is the drying time for most sealers?

A. There are two types of concrete sealers: topical and penetrating. The best sealer to use is the long-term penetrating type. If the concrete driveway has not been sealed before, it is a good candidate for a penetrating sealer.

Topical sealers should be reapplied almost yearly. You should be able to find a penetrating sealer in building-supply houses. Read the manufacturer’s instructions before buying the product to be sure that you understand when is the best time, and how, to apply it, and how long it takes for the sealer to dry.

Q. I own a 1970s-era ranch home (26 feet by 42 feet) with gable vents at the ends. I had a 24-by-26-foot addition put on it. The builder did a roof ridge venting system on the addition and insisted that no gable vent was needed on the end of the addition for proper airflow.

The main home now can only vent into that addition — although it is not a straight line anymore as the addition was offset eight feet. The gable vent on the west end is still there. On east side, the original vent was moved over 10 feet to vent into the addition’s attic roof.

The builder’s notion is that the air will still find its way through the main ranch attic from the offset opening of the main house into the addition and then up through the roof line vent in the addition. Is this true? Is this sufficient? Seems like airflow will be severely restricted.

Should the house addition have a gable end roof vent as well? The builder refused to install both, saying it would confuse the air. I’m worried about mold, mildew and too much heat in the attic as a result of airflow possibly being impeded.

A. If the addition has continuous soffit venting on both the front and rear of the addition, and an unobstructed air space between the soffit vents and the ridge vent, the builder is correct. If the addition does not have soffit vents, a ridge vent alone is not effective in venting an attic.

Gable vents should not be used in conjunction with the ideal venting system described above, as it eliminates the proper venting of the lower parts of the roof.

I disagree with your builder that the air will find its way through the labyrinth created by the new construction. However, if the venting of the main house attic is solely by means of gable vents, and you have not noticed any mold or other signs of moisture, there is no reason to be concerned.

Since the addition is offset by eight feet, it seems as if the gable vent on that end of the house should be able to be retained.

Q. The last two times I had my cedar deck railings sanded and stained we used a product you recommended which I could buy at Essex Paint on Route 2A in Essex, Vermont. I believe it was an acronym.

It was pretty toxic. This time, the people who will work for me will only do it if I have a less toxic product. What do you recommend now, please?

A. Amteco TWP 1500 Series is EPA registered, as all Amteco’s products are, but has a lower VOC formulation. It replaces other Series in states where they have been banned because of their higher VOC formulations. TWP is still my favorite product to use.

• Henri de Marne was a remodeling contractor in Washington, D.C., for many years, and is now a consultant. His book, “About the House,” is available at www.upperaccess.com. His website is www.henridemarne.com. Email questions to henridemarne@gmavt.net, or mail First Aid for the Ailing House, Universal Uclick, 1130 Walnut St., Kansas City, MO 64106.

© 2016, United Feature Syndicate Inc.