WRB over fiberboard sheathing
bryanw511
| Posted in Green Building Techniques on
As part of a whole house remodeling project, were going to be replacing the siding on a house built in 1979 which was sheathed in asphalt impregnated fiberboard (blackboard, celotex, etc.). Does anyone know of a self adhered WRB that will stick to it? If not, what would you suggest in this situation?
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Hi Bryan.
When I remodeled an exterior with fiberboard sheathing I wasn't satisfied with the adhesion of any off-the-shelf tapes (available at local lumber yards/big box stores) that I tried. At the time my solution was to install mechanically fastened housewrap, detailed as meticulously as I could, and then to detail a layer of exterior rigid foam as an air barrier as well. The redundancy made a considerably improvement in the comfort and efficiency of the house. But that's just tapes and I believe that there may be some products that claim to adhere to fiberboard. Check out SIGA tapes.
I haven't looked into any fully adhered WRBs and compatibility with fiberboard sheathing. I wouldn't be surprised if they could work, perhaps with a primer applied first. You may also look into fluid-applied WRBS for a water and air barrier on the fiberboard sheathing.
If you have success with one of these products, please report back and let us know. Lot's of older houses have this type of sheathing and often it is advantageous to leave it in place.
Thanks for the info. I did contact Henry (Blueskin VP100) and Grace (Vycor enV-S) and they both essentially said We're not really sure if it would adhere correctly. Maybe if you used a primer it'd work.
I don't want to be the guinea pig and try putting a self adhering membrane over fiberboard if there's no proven way to do it successfully.
I'll probably do just what you did, install a good quality mechanically fastened WRB as meticulously as possible.