Consider insulating options

How can I insulate the walls of my doublebrick house? The place was built in 1950. One contractor says he can drill holes in the plaster and blow insulation into the space between the bricks, but another says this won’t work.

Even though it’s summer, boosting home heating efficiency is still worth planning for. And though it’s certainly possible to drill holes and try to blow insulation into your walls, chances are the space is choked with hardened bits of mortar that fell into the space as the bricks went up.

This would prevent loose insulation from getting into every nook and cranny and, even if it did, moisture would probably be a problem.

Bricks aren’t good at keeping rainwater out, especially old bricks. That said, injecting slow-rise foam into the wall cavity holds a lot more promise.

You can do this work yourself using a spray foam kit, and slow-rise formulations are made so the foam expands and creeps slowly into wall cavities. It works especially well in hollow wood frame walls, but works for brick if you take special measures to “see” where the foam goes, drilling and spraying accordingly.

Tiger Foam ( tigerfoam.ca; 888-8443736) is the only source of slow-rise spray foam kits that I know of in Canada. This material gives off heat as it cures, allowing you to use an infrared camera to see where the foam has and has not crept in.

Another approach involves applying two inches of extruded polystyrene foam to the inside or outside face of exterior walls. This is a big job involving tricky finishing work around windows and doors, but it does work.

What’s the best way to build a deck so it lasts? Is composite lumber the way to go?

Composite deck lumber never needs finishing, but it can only be used on the top of the deck where you walk. Structural elements still need to be wood and how posts and beams and joists go together affects rot resistance of a deck to a significant degree.

The main thing to understand is that trapped moisture within the structure promotes rot. This is why it’s vital to design your deck to reduce wood-to-wood contact areas as much as possible.

Will your design include beams? Most do. Use solid six-by-six or eight-by-eight pressure-treated timbers instead of spiking together several two-by-eights.

Also, wherever deck boards meet end-toend, install two joists side-by-side with a one-inch space between them. This allows you to keep the ends of deck boards 1/8-inch apart so water trickles away instead of being held between vulnerable end-grain surfaces, promoting rot. Details like these are important enough that I’ve written a book about it.

Also, it’s essential that you use hot-dipped galvanized, stainless-steel or ACQ-rated fasteners to secure today’s pressure-treated wood. The chemicals used to inhibit rot cause ordinary nails and screws to corrode quickly.

Can metal roofing be applied directly over old shingles?

If the existing shingles and roof are flat and reasonably sound, it’s OK to install metal roofing on top. If the old roof is wavy and uneven, you may need to install strips of wood across the roof, shimmed to level things up.

Metal roofing is an attractive, long-lasting option. The first thing to go bad with metal roofing is the appearance of the finish, so you should definitely check out the warranty before you buy.