Caulking Siding Joints

Similar to weatherstripping caulk strips are pre shaped rolls of sealant that have a peel and stick installation.

Caulking siding joints.

The answer depends on the manufacturer and installation method used when the siding was first installed. When james hardie siding products butt into wood based materials a 1 8 gap will allow for expansion and contraction of the wood based product. When deciding how to use caulk on your siding however it is generally more important to consider where you should not use it. Sometimes the old caulk in the siding joint is cracked and you need to cut the old caulk out with a razor knife.

James hardie also does not recommend applying caulk to the horizontal overlap between siding planks see figure 2. Caulking around windows doors eaves and trim edges gives added insurance that leaks will not occur. Those joints need to be protected somehow. Where two pieces of siding meet.

Joint flashing butt joint horizontal lap treatment june 2014 james hardie does not recommend caulking butt joints or the horizontal overlaps joint flashing 6 in. Caulk backer rods are lengths of foam that help fill large gaps before caulking. Butt joints but not all butt joints. Apply these strips in place of traditional caulk or over already caulked joints for a finished appearance.

25 4 mm on overlap no caulk figure 1. 152 4 mm wide 1 in. While as a diyer you might be obsessing about your caulking skill truth be told that will not matter if you don t have the right caulk. Natural siding boards are designed to expand and contract.

If overused or incorrectly placed siding caulk can cause more damage to your exterior than good. These siding joints can be caulked successfully if the gap is wide enough for the caulk to get into the crack. It is generally not a good idea to use caulking on wood siding. Generally we do not recommend caulking butt joints on cedar siding.

Joint flashing is recommended for all hardie lap siding now. Although i do not understand why they have not changed the information about caulking in the instruction manual. Caulk is the durable waterproof paste that s used as a sealant in joints and gaps to keep dirt pests moisture and exterior air at bay. Should they always be caulked.