How to improve window trim

Q. I have had Pella replacement windows for about 20 years. The windows on the rear of my house face south. The vinyl window trim and screen frames have faded over the years. The vinyl is a dark architectural brown. Can the vinyl be repainted? The inside is stained wood, so there is no problem. I intend to have the screening replaced, and if it is possible to do, would prefer to repaint the screen frames prior to replacing the screens. I live in a suburb just northwest of Chicago.

A. Twenty-some years old Pella replacement windows were clad in aluminum. Vinyl didn't come on the scene until several years later.

This is what Pella recommends: "If the customer paints the product(s), Pella advises to discuss exterior paint quality with a local paint supplier. The better the quality of paint, the longer it will last.

"Two types of paint are available to top coat Pella clad products: Latex and oil-based. Latex paints are easy to use because they thin with water and offer the advantage of easy cleanup. Oil-based paints must be thinned with solvent and cleaned up with mineral spirits; however they are generally a longer-lasting top coat.

"Semi-gloss or gloss paints will shed dirt and water better than flat paints. Lighter color paints will resist expansion and contraction due to the sun's energy better than dark colors. It is best to avoid a dark-colored, flat paint.

"If the product is less than one-year-old, scuff sanding is necessary. If it is older than one year, sanding can be skipped. Before painting, make sure the metal is clean and dry. Metal preparation is an option to be certain the cladding is clean (metal prep can be found at most auto part stores).

"Pella recommends using a good china bristle brush to apply paint by hand. Care should be taken to avoid getting paint on the weatherstripping. Two top coats of paint will give the best coverage and longest lasting finish.

"The paint warranty is voided if the factory finish is altered."

Best of luck.

Q. I live in a tri-level home and need to replace the roof. The underlayment wood consists of wood planks about 7.5 inches wide and 1 inch thick. There is a gap (shown) between the boards of one-quarter to one-half inch or so. Some need replacing because of knotholes and a few have breaks.

I was told by a roofer that they apply three-eighths inch plywood over the entire substrate because the nails that enter the gaps may cause leaks. Do you agree, or is replacing the boards that have failed all that is necessary?

I am aware of the key part ventilation has in a roof. There are two separate roofs; the lower section is above a vaulted living room and dining room. I had soffit vents cut in (and baffled) in both roof sections a number of years ago. Would a ridge vent be the best solution for the lower roof, which now has a few roof vents? We get a considerable amount of snow and wind in the Chicago area. If so, what is the best choice for a brand? (There is no gable vent).

What about the upper section, I assume that roof vents are the best solution on this part. I currently have an attic fan that I have discontinued using and will remove. Is there a calculation for the number of roof vents needed? The bathroom fans vent out through the roof to prevent potential mold growth.

A. Thank you for the photos; they are helpful for me to answer your questions.

I can see why your roofer is suggesting applying a layer of plywood over the existing board sheathing; one of the photos shows a significantly damaged board and you mention that there are several more; they can be replaced.

The gaps between the boards in the other photo do not present a problem and roofers should be able to nail the shingles and avoid them; it's been done many times. The additional expense does not seem worthwhile.

Ridge vents in combination with soffit vents are always the best natural roof ventilation, but the combination requires an effective air space between the two. Since you have a vaulted ceiling in the lower roof, you will need to make sure such a space exists, as it is possible the rafter spaces are filled with insulation.

The best ridge vents are those that are externally baffled to deflect the wind over the roof ridge. They are also the ones least prone to admit windblown snow and rain into the attic. My favorite one is Shinglevent II; there are others similarly baffled externally.

The upper roof looks like a hip roof, but the trees behind make it difficult to see the roof line clearly.

If it is indeed a full hip roof, you can install the same ridge vents on the hips in combination with soffit vents. Individual roof vents or turbines are not very effective.

As long as soffit and ridge vents are continuous and full-length, there is no concern about calculating the ventilation.

Although venting bathroom fans through a roof is not the best way to do so in cold regions because condensation can run down and affect the fans' works, wet the insulation and damage the ceiling, you may not have a choice because you do not have a gable wall to vent them. Bathroom and kitchen venting should not be done through soffit vents, as the exhausting moisture would be drawn back into the attic.

Q. We are going to be building a new deck with a pergola. In your opinion, which is better - Trex or Azek?

A. Both are composite decking; there are many more on the market.

There have been reports of problems with both Trex and Azek, which have both suffered lawsuits as a result. You probably should make the decision based on your preference of the looks of the product.

I am sorry not to be of more help, but I have never had personal experience with Azek while I have had for many years with Trex. But that doesn't mean that I recommend Trex over other composite decking.

Q. In my former house I replaced the broken sash cords with plastic spring loaded tracks I bought in a hardware store. They were easy to cut to size and slip in on both sides of the sashes and did a decent job of sealing drafts as well (and cheaper than replacing the sashes). I think they were called cpw or crw. I can't find them anywhere now. Do you know where I can buy them?

A. If they are still available commercially, you should be able to get them at Blaine Window Hardware Inc. in Hagerstown, Maryland. Its website is www.blainewindow.com, and the toll-free phone number is (800) 678-1919.

• Henri de Marne, a former remodeling contractor turned columnist and consultant, is the author of "About the House with Henri de Marne" (Upper Access Publishing). He continues to take questions from readers for this column and his website, www.henridemarne.com. Email questions to aboutthehouse@gmavt.net.