WRB for Flip
alcoprop
| Posted in General Questions on
Hey guys, I am a full time rehabber/flipper and I just bought a house to flip on Norris Lake in TN. Siding and windows need to be replaced and upon inspection the house has vinyl siding, 1/2″ green insulation board from Lowes, 7/16″ osb. No housewrap or WRB of any kind. With keeping cost in mind what would be the best economical thing to do for a WRB? I am normally a zip guy but it would not be worth stripping the current osb obviously. Should I just properly install Tyvek? or?? Thanks!
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Replies
Shaun,
The least cost option would be #15 roofing felt but that won't increase airtightness. For that you would either need to prime and tape the OSB seams or use a housewrap with compatible tape, like Tyvek.
Some insulation boards can technically be considered a WRB if detailed as such but I've never trusted it. Foam shrinks. Tapes and sealants won't hold to it for long in such an exposed location.
Yeah I would never do something like felt paper. I guess I should have said I don't want to be completely cheap, I just want something that will be a good WRB and not blow my budget like taking all the osb down and replacing it with zip would. I have never really been a tyvek fan but I know when it is properly installed it will do a decent job. I also probably will not go back with foam on this job. Was going to focus on a good WRB and airtightness and then probably Rockwool on the interior.
Look at Mento or Majvest, not cheap, but not as much as Zip
With OSB already present, use it as a base for approximating a Zip installation. Establish an air barrier by taping the joints with a good tape. I've used Zip tape on plain OSB with great results, and the "Backyard Tape Test" on this site confirms that it works well. Then plain Tyvek along with the proper flashing for a no-frills but durable WRB. Too bad about that 1/2" rigid foam--maybe re-install it on the exterior doubled up into a 1" layer, then add enough 1" polyiso to cover the rest of the house. Boom, you've got a 99th-percentile envelope that an appraiser likely will completely disregard, but maybe an energy-minded buyer will appreciate it.
I like it! Thank you.