Sealing Siding Joints

2 house built before 2008 so has no flashing okay to caulk.

Sealing siding joints.

Lp siding requires flexible exterior grade paintable caulk to seal gaps. 1 to all roof coverings. On older installations of hardieplank lap siding the field butt joints would have an appropriate gap which at one time was specifically designated as 1 8t. A common problem with cement board siding products and some other types of horizontal lap siding is that older installation guidelines called for caulking the joint instead of flashing the joint.

Metal flashing or any metal to wood joint should not be caulked another water exit pathway that should never be sealed. Two appropriate products are polyurethane and solvent based caulk. Butt joints are a perfect example of poor joint design they re too small to accommodate a bond breaker so the caulk can t stretch properly once applied but they re also too large to simply leave alone. 1 i chose this caulk because it has 25 flexibility compared to silicone based caulk.

Siding nails should not be caulked another item that needs room to play is siding boards themselves. It is great for sealing a wide range of places around the house from doors and windows to bathtubs and siding. Also avoid caulking tongue and groove siding boards together. This has proven problematic over time as caulking the joint results in unsightly surface appearances due to the different textures as well as resulted in failure of the caulk joint and associated ongoing maintenance.

Weather proofing butt joints in building siding in most climates it is a good idea to slip a small spline of asphalt felt paper behind each butt joint in horizontal sidings. Although lp building products siding is available bare or painted cutting the materials to fit during installation exposes some areas to the elements. 3 16 gap at butt joints between horizontal sections and where the siding meets doors windows and corner trim. The nails holding up the siding should not be caulked.

A lot of moisture from rain snow misdirected sprinklers or exuberant water fights can get in there enough to do some serious and expensive damage. 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. The irc requires that horizontal lap sidings have a minimum one inch lap joint or 1 2 inch if the siding is rabbeted.