Caulking Old Wood Siding

Scoring prevents the wood from chipping when you cut it.

Caulking old wood siding.

Do ride the smooth edge when caulking a seam between a window and textured siding. In the old days the builder would install the trim bring the siding up to it and caulk the corner. Caulk by its adhesive nature will try to limit this movement leading to widespread failure and cracking in the caulk over time. Pull out loose nails and renail using stainless steel siding nails.

Caulking on the exterior siding joints at the corner board if done carefully does not need to be smoothed with a finger. The siding expands and contracts with temperature and humidity. On most new homes the trim goes up after the siding is installed which creates a large gap that should not be caulked. Even an old outbuilding can benefit from a little caulking.

Many professionals like those at james hardie also agree that you should not use caulk on fiber cement siding unless there is no metal flashing underneath. When you try to restrict either it is at your peril. We used a high quality acrylic caulk on our barn to seal the corner joints seams and trim pieces around doors and windows. Score the cut line with the utility knife guided by a square.

Siding is often textured and if you slide the tip of the tube along the bumpy texture the bead of caulk will. Trim boards that sit on top the siding. When it comes to things like old windows traditional glazing putty is a much better choice. Caulk prevents water from seeping behind vulnerable areas of the outbuilding and developing into rot.

Most other areas were caulk is necessary should be lightly smoothed with your finger. The hole should be about 3 16 of an inch for most caulking joints. Removing all the silicone is difficult to accomplish as there is almost always some residue and when you remove it from wood it inevitably grips onto the wood fibers and pulls them with it resulting in a mutilated work piece that requires lots of repair. It needs to move and breathe.

Be sure to remove any caulk where the siding overlaps as old houses need to breathe. Think of a wood home as a living thing. Apply an epoxy consolidant to soft wood and coat the rest with. Line up the ends and using the old piece as a guide mark the new clapboard with a utility knife.

Fill any dents and holes with either a wood or epoxy filler. Placing caulk over large portions of wood siding prohibits the natural movement of the wooden panels and can cause extensive damage to the exterior of your home.