Caulking Cemplank Siding

Vertical trim gap caulking.

Caulking cemplank siding.

A mark parlee a general contractor in des moines iowa responds. Always prime or paint any cut edges that are inserted into a window j channel. Dents chips cracks and other minor surface damage in james hardie siding and trim products can be filled with cementitious patching compound. Caulking sealant must be applied in accordance with the caulking sealant manufacturer s written instructions or astm c1193.

A diyer or a novice painter might attempt to achieve a cleaner look by caulking the siding nails but the nail is guaranteed to push the caulking material out within a few months. V caulk replacement when sealant is in need of replacing carefully remove existing caulk and replace with a high quality paintable latex caulk. The nails holding up the siding should not be caulked. Leave a 1 8 gap between the siding and the trim or other materials to allow for structural movement.

For best results use a latex caulk that complies with astm c 834 astm c920 or better. Cemplank lap siding and cempanel vertical siding can be installed and finished like wood. Do not caulk between siding and any built in receiving channels located at or around windows. In my experience water that gets trapped against fiber cement siding can be absorbed by the material causing joints to swell and shrink during freeze thaw cycles.

On our jobs we typically don t leave gaps for caulk at butt joints because this detail can contribute to the problem. Instead we snug the joints up tight and. Cemboard fiber cement siding products are an attractive and durable alternative to vinyl and wood based siding. Always caulk between the siding and the trim.