Cement Board Siding Seams

James hardie believes it is good building practice to seal the joints to prevent moisture such as wind driven rain and snow from penetrating the wall cavity.

Cement board siding seams.

James hardie 8 25 in x 144 in hz10 hardieplank cedarmill fiber cement lap siding. We only caulk butt joints on cedar siding if previously caulked. It is a very simple process and i used some fibatape and thinset mortar to seal the cement board j. Trim boards wood windows.

In this video i show you how to tape cement board joints. For pricing and availability. Hardieplank the classic flagship james hardie product is a simple 5 16 inch thick by 12 foot long lap siding in widths ranging from 5 1 4 inch to 8 1 4 inch. It s available in a variety of sizes and shapes to match many of the old siding shingles installed over the last 60 years.

Our siding close up photo at page top illustrates what may be another clue in the history of a failed installation. This article series includes field reports of fiber cement board lap siding butt joint gap. Some manufacturers do not require the metal flashing therefore we caulk the butt joint to keep the pieces together and also prevent moisture. Fiber cement boards are caulked only when there is no metal flashing behind them.

Traditionally board and batten siding starts with wide vertical planks boards which are then joined together by thin vertical strips battens to cover the seams. Buckled fiber cement siding is most likely to occur because the installer failed to give the recommended gap between the ends of the fiber cement boards and abutting vertical trim at corners windows doors etc. Homesteaders and farmers would use sawmills to cut the long boards and the battens were put in place to make the structure as airtight as possible. Fiber cement siding accessories.

Manufacturers caulk and sealant recommendation sheet s 100b issued july 2000 application. For pricing and availability. 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. It does nothing else but produce fiber cement siding and cement backer boards.

We can see a hard dried layer of caulk that was a bit under 1 8 inch wide inside of the now wide open butt joint between two siding boards.