I can see this is a UK based forum. Maybe someone can help anyway, or suggest a high traffic US based DIY forum?
I have a small wooden house on cinder blocks in Gainesville, FL (North Central Florida: considered a hot humid climate, but it can get cold in winter sometimes). It's a common post war type building often referred to as a "cracker" house (although technically a cracker house is a very specific style and construction that this is not). It has 2x4 wall studs (designed by a crazy person) and an unsheathed metal roof.
The walls have a type of scalloped board as siding (and sheathing... just one layer total), and thin paneling with plaster in the interior. There is zero insulation in the house, but for an insane mountain of some kind of fluffy stuff in the attic.
I have some insect damage, so I pulled all the siding off the front of the house and screwed up pressure treated plywood. Now I want to unscrew that, replace all the studs (there a reason, too long to explain), insulate, and then replace the windows.
General plan: Replace wall studs section by section, add fiberglass batt insulation, have exterior grade OSB on the *interior*, and then pressure treated plywood as the initial exterior wall. As the budget permits, then a layer of rigid foam over the plywood and a final layer of Hardi board (cement fiber siding, looks like wood siding). Then plasterboard in the interior etc.
So getting to my question (finally, sorry):
-How do I avoid trapping moisture in the wall during the long hot humid summer? There will be lots of heat and moisture outside and lots of cold air (AC) inside the house. I'm a displaced Northerner, where I think the vapor barrier was behind the plasterboard. Down here, I think it's opposite, underneath the exterior.
So with my plan of OSB, fiberglass batts, and plywood, do I need an additional vapor barrier? Both the OSB and the plywood are effectively vapor barriers, should I use a house wrap *under* the plywood to act as a drainage plane to wick out moisture? Or would the house wrap/drainage plane be after the plywood when I finally get to adding the foam board and the Hardi board? Of course the foam board is a vapor barrier as well.
Pardon my verboseness and hopefully the core of what I'm asking is clear.
Thanks,
John
I have a small wooden house on cinder blocks in Gainesville, FL (North Central Florida: considered a hot humid climate, but it can get cold in winter sometimes). It's a common post war type building often referred to as a "cracker" house (although technically a cracker house is a very specific style and construction that this is not). It has 2x4 wall studs (designed by a crazy person) and an unsheathed metal roof.
The walls have a type of scalloped board as siding (and sheathing... just one layer total), and thin paneling with plaster in the interior. There is zero insulation in the house, but for an insane mountain of some kind of fluffy stuff in the attic.
I have some insect damage, so I pulled all the siding off the front of the house and screwed up pressure treated plywood. Now I want to unscrew that, replace all the studs (there a reason, too long to explain), insulate, and then replace the windows.
General plan: Replace wall studs section by section, add fiberglass batt insulation, have exterior grade OSB on the *interior*, and then pressure treated plywood as the initial exterior wall. As the budget permits, then a layer of rigid foam over the plywood and a final layer of Hardi board (cement fiber siding, looks like wood siding). Then plasterboard in the interior etc.
So getting to my question (finally, sorry):
-How do I avoid trapping moisture in the wall during the long hot humid summer? There will be lots of heat and moisture outside and lots of cold air (AC) inside the house. I'm a displaced Northerner, where I think the vapor barrier was behind the plasterboard. Down here, I think it's opposite, underneath the exterior.
So with my plan of OSB, fiberglass batts, and plywood, do I need an additional vapor barrier? Both the OSB and the plywood are effectively vapor barriers, should I use a house wrap *under* the plywood to act as a drainage plane to wick out moisture? Or would the house wrap/drainage plane be after the plywood when I finally get to adding the foam board and the Hardi board? Of course the foam board is a vapor barrier as well.
Pardon my verboseness and hopefully the core of what I'm asking is clear.
Thanks,
John