Caulking tips

Caulk seals the seams of a house's shell, preventing water, cold and hot air, and pests from getting in. Here are tips to get you started.

Want to keep your house well sealed and watertight? Caulk here:

• Along seams at inside corner mouldings
• Along seams at outside corner mouldings
• Along joints where siding meets the foundation
• Along joints between door frame and siding
• Along joints between window frames and siding
• Around vents from dryer, bathrooms, and kitchen
•  Around through-wall holes made for outdoor electrical outlets or lights
• Around through-wall plumbing pipes and utility lines
• Along joints between flashing and the chimney and around the chimney flue where it meets the crown
• Along the joints between the foundation and a patio or porch

• Every so often you'll need to caulk an area that's hard to get to. Use a piece of duct tape to affix a piece of plastic tubing or a plastic drinking straw to the end of the tube nozzle. You'll still need to guide the caulk into the seam, but the added length can make the job much easier.

• Don't waste caulk trying to seal a gap that's wider than half a centimetre (1/4 inch), or deeper than one centimetre (half an inch). Chances are it won't hold up, and you'll soon be buying more caulk to do it over the right way.
• The way to approach a deep crack is to press a backer rod (available in different sizes at most hardware stores) into the gap before you caulk. The rod lets you tool the bead more effectively, and provides an additional support surface that lessens stress on the caulk.

• If you've stripped your siding down to bare wood (or have new siding) the correct order is to prime the bare wood first, caulk the seams, then paint.