Hardie Board Over Asbestos Siding

Hold your backer board firmly in place and use corrosion resistant screws to install your backer board to the home.

Hardie board over asbestos siding. James hardie is the world leader in fiber cement siding and backerboard. Below are photos of a recent job we did siding over the t 11. Although i do not recommend siding over existing siding i suppose a case could be made for doing so if you had an asbestos shingled house that was in great shape and you wanted to retain the fire retardant protection of the asbestos but still reside the house cheaply. Something you will want to keep in mind when making this decision is how long hardieplank will be on your home.

T 111 is one of the easiest prodeuct to side directly over. Most siding companies are well experienced at techniques for covering over existing asbestos cement siding with new vinyl aluminum or fiber cement siding. Wrap asbestos siding in 6 mil thick plastic sheeting and secure the plastic with duct tape or place the debris in heavy duty plastic bags. It is best to just replace the asbestos siding but that can be very expensive.

Do not throw or drop removed asbestos siding. The actual question is should the current siding be removed with osb installed or should the current siding remain to act as a substrate an additional layer beneath the top layer under the new hardieplank siding. We ve been providing a better way to build for over 100 years. Select one area of the house at the bottom of the house to work on and start there and work your way up.

Asbestos siding is made of the same product but exists in a hardened state and does not pose the same type of threat as asbestos insulation. This however can change if the asbestos siding begins to dry out or get damaged. If you remove the t 111 and disturb the asbestos you will have to have it abated which will cost thousands of dollars. Since the screws will be going through the asbestos siding this step is critical.

I recommend placing the hardie siding directly over it. Work from the top down removing the snails to keep from breaking the asbestos siding. More than 50 years. This will look terrible and likely void the warranty.

If not the lap spacing on hardi is different than asbestos which will create a wave pattern on the hardi.