Staples may be a good alternative to some adhesives

Q. I put plastic lattice under my outside deck to dress it up. I tried to glue window screen on the back of the lattice to keep flying insects out, but the screening keeps coming loose.

What type of adhesive do you suggest?

A. I am not sure that any adhesive would work on the plastic lattice, but if you haven't, you may want to try construction adhesive.

Instead, I suggest that you staple the screening to a piece of pressure-treated lattice and screw it to the plastic lattice with stainless steel screws every 2 feet or so.

Q. In September 2013 we replaced our oil furnace and a broken A/C unit with the top-of-the-line Carrier Greenspeed heat pump and electric air handler.

The chimney that was used by the oil furnace was no longer needed and it was capped off inside the basement with cement, but the top of the chimney remains unchanged. Should we cover, cap or leave the chimney as-is to prevent precipitation or anything else from getting into the chimney?

I've sent you three pictures of the chimney, including one looking down inside the chimney. Note that this chimney was extended when we added an entire second floor to our then-one-story home about 17 years ago. Also, a couple of the bricks at the top row are loose, so I need to lay some new mortar in the spring.

A. Yes, you should secure the loose bricks with mortar and cap the chimney. Not only can weather enter the chimney, but it would also be a welcome home for raccoons, squirrels and birds.

Since the top of the chimney is approximately 16 inches by 34 inches, you can cap it with several roofing slates laid across the 16-inch dimension. Roofing slates come in several lengths from 12 to 24 inches. The 16-inch-long slates are 8 inches wide, so four slates should do it.

This will be easier than lugging a larger slate to cover it with one piece.

If you haven't experienced leakage from the base of the chimney and the roof, you are fortunate, as the step flashing is not done right, based on the pictures sent.

Q. Thank you for all the very useful information that you provide to homeowners and others. I've referenced you and your advice on quite a number of different topics through the years to people who evidently don't get a newspaper with your columns. I'm grateful for all that I've learned from you.

I have an unusual situation, I think. About 20 to 30 years ago, I installed a bathroom exhaust vent pipe through a gable wall of my house. The fan is axial and vents into a galvanized steel reducing ell, like one that might be used in heating ducts. This is attached to a 6-inch diameter green plastic pipe about 18 to 19 feet in length. This arrangement has worked fine all these years, and still does.

However, in the summer of 2014, we began seeing a faint yellowish discoloration of the grid covering the fan inlet. Later on we began seeing the same discoloration, faint at first, but becoming brighter yellow, on the ceiling and walls surrounding the fan and extending to the floor of the bathroom. Today, using a mirror and flashlight, I examined the ductwork and found something clinging to the inside wall of the plastic pipe and the transition piece. We have no idea what it could be.

I'd like to try removing this deposit without disconnecting the ducting and transition. Have you ever encountered this problem previously? Any idea what it could be, or what may have produced it? (It looks like it is some kind of fibrous material or dust clinging to the inside surface of the ducting.) Any thoughts as to what may work to remove it, and prevent a recurrence of it?

On the fan inlet grid, the coloring is something akin to a lemon. Any ideas, and any preventive treatment to preclude it happening again would be much appreciated.

A. I have never heard of this condition before, so the only thing that comes to mind is that, after all these years, the plastic pipe is disintegrating. If this is the case, the only remedy would be to replace it with a metal pipe.

The mystery only deepens with the discoloration on the ceiling and walls extending to the floor of the bathroom. This would seem to indicate a considerable amount of backdraft from outside through a leaky exterior wall jack.

If anyone has any ideas, please let me know, and I'll pass them on.

Q. I have a handcrafted maple table that has no finish on it. Unfortunately, a vase on it had water that overflowed, staining the wood a green color. I believe it is too deep to remove with sandpaper. What else can I do?

A. If the table is a valuable antique, it is best to take it to a professional furniture restorer. Otherwise, try to remove the stain with chlorine bleach. First, apply the bleach full-strength to the stain, and then follow this by applying it immediately over the entire tabletop with a clean white cloth. This will prevent a bleached area where the stain used to be. If some of the stain remains after 20 minutes or so, apply more of the solution to the stain.

But if this does not remove the stain, try oxalic acid. Buy a small amount of the crystals in a paint store, dissolve them to saturation in very hot water in a glass container (never use metal with oxalic acid, a very caustic chemical) and apply the solution to the entire top as above.

Allow the solution to work for 20 minutes or so, and neutralize the acid by wiping the entire top with a solution made of a very small amount of ammonia (about one tablespoon) to a quart of water. Wipe the wood dry with a clean white towel and rinse the tabletop again with clean water. Dry it with a clean white towel.

Use rubber gloves and skin protection.

Any solution applied to the wood will cause the grain to raise slightly. Sand the tabletop lightly with fine sandpaper.

You should consider applying a sealer to the tabletop to prevent a recurrence.

Q. We are doing a renovation project that has used a lot of wood - poplar for trim, sheets of bead board made from MDF on the walls, and lauan for ceilings.

Fairly large gaps have appeared in some of the seams (up to one-eighth inch in places) in this dry winter air.

We are now preparing this wood and trim for painting with latex paint. What is the best technique for filling these gaps before painting, and when is the best time to do it?

Interior latex caulk fills them perfectly - now - but what will happen later when the wood expands again? Is it safe to fill these now, and paint, though the wood may well expand again in the spring? (For the smaller gaps and nail holes we are using Dex "pink" filler.)

Are there techniques or products you suggest that will maximize the effect of the caulk?

A. I am concerned that as the wood expands during the summer's humidity, the caulking may be squeezed and look pretty bad.

I suggest you wait until the summer's humid air closes the gaps, at which time painting all the wood, including all accessible edges, should seal it enough to reduce or prevent the wood from shrinking again next winter.

It would also be helpful to maintain a desirable relative humidity of 30 to 40 percent in your house throughout the winter.

Q. Our house was built in 1995. We have Crestline windows, which, I think, have been discontinued. The storms were added later, perhaps in 2000.

I looked up the Mortite rope caulk at Amazon. It only seems to come in brown and gray. Our windows are all white. The gray wouldn't look too great, but it looks like a great idea. Maybe I can find the white rope caulk somewhere else. Does Mortite make it in white?

Our windows are doing better than last winter, with less frost on them. I don't put down the blinds till I go to bed. I think that helps, too.

A. I am not aware of any white Mortite. You may have to accept the gray for the duration of the winter.

Q. I am hoping you can suggest something to use to wash bathroom walls that have hair spray residue on them. I do not want to damage the paint, so I am reluctant to try some of the products I have looked at.

A. Your bathroom walls are likely to be painted with a semi-gloss paint. So mix one part fabric softener to two parts water in a spray bottle and shake well. Let it do its work for a half a minute or so and wipe it off with a clean, damp cloth. You may have to make several applications, depending on the thickness of the buildup.

Rinse the treated area with another clean, damp cloth to remove all residue of the fabric softener.

Do not rub too vigorously, as it may damage the paint.

• 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.

© 2015, United Feature Syndicate Inc.