Best Caulk For Hardie Plank Siding

0 312 in x 8 25 in x 144 in hardieplank primed woodgrain lap fiber cement siding panel.

Best caulk for hardie plank siding.

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. Re applying caulking when it has begun to show signs of wear can help keep moisture from getting into the wall cavity. This from installation instructions. Fiber cement siding repair or patching.

For best results use caulks that comply with either astm c 834 or astm c 920. Any lower and you might see a few nail heads poking through the bottom of the next board any higher and your siding is likely to be loose and. For best results use an elastomeric joint sealant complying with astm c920 grade ns class 25 or higher or a latex joint sealant complying with astm c834. James hardie recommends the use of caulks and sealants that remain permanently flexible.

Once all caulk is dry and your siding is clean you ll paint hardie plank with a high quality exterior grade acrylic latex. Hardy plank cannot be stained. Trim boards that sit on top the siding. James hardie does not recommend the use of caulk at field butt joints.

Hardie plank siding has a nail line across the top of the board that is 1 down from the top and nails are supposed to fall between and 1 from the top of the board to give the best hold. Do not use stains or oil based alkyd paints on james hardie products. In the old days the builder would install the trim bring the siding up to it and caulk the corner. For regular hardiplank lap siding the kind you paint after installation caulking at butt joints is optional.

A high quality paintable caulk is recommended. For additional information on finishing james hardie products download technical bulletin 22 from here. On most new homes the trim goes up after the siding is installed which creates a large gap that should not be caulked.