How to Caulk HardiePlank Siding
- 1). Open the end of a tube of latex caulk with the cutting handle of the drop-in caulk gun. The cut should be 3/16 inch wide and be on a 45-degree angle.
- 2). Place the opened latex caulk tube into the drop-in caulk gun.
- 3). Squeeze the handle of the drop-in caulk gun and pull the caulk gun along the lowest horizontal lap seam between two installed lengths of the HardiePlank siding. Move up one seam and repeat the procedure.
- 4). Soak a clean rag in the 1-gallon bucket of water.
- 5). Place the wet rag over an index finger and run the rag over the caulked seams to blend the caulk into the HardiePlank siding.
- 6). Caulk and smooth two HardiePlank seams at a time until all horizontal seams are sealed. Allow the horizontal seams to dry for 24 hours.
- 7). Apply caulk to the vertical seams and smooth the caulk with the rag. Apply caulk only to vertical seams that are close together to avoid the possibility of the caulk curing before it has been blended into the siding.
- 8). Caulk and blend the butt joints of the HardiePlank siding to complete the caulking process. Allow all caulked joints to cure for at least 24 hours before applying paint to the sealed siding.