Originally Posted by sloper
Rob, bought your book years ago. It's an awesome resource.
Thanks for the kind words..... (by the way - it's Rod not Rob
I'll be purchasing the bay so no lease or landlord to worry about. John, reusing the old drywall is a great idea, I'll definitely be doing that if possible. It's a lot of work, but it is the best way.
A relatively easy way to do that is to cut the drywall flush to the edges of the stud bays using a reciprocating saw..... just be careful not to go any deeper than the back face of the drywall to avoid cutting any electrical wires (or other cables/pipes, etc.) that might be inside the wall... after that you can always leave the remaining strips of drywall on the studs. A bit of a trim on the edges and you are ready to reuse the drywall in the stud bays..
Having said that though I have to caution you.... you really might want to run that buy the local Fire Marshall first...
Although I do not know why this might affect the fire rating of the wall assembly - here in the states the code requirements are that the assembly be "rated and tested" - and I have never seen a rated tested assembly that was constructed in that manner.... meaning a layer of drywall installed within a stud bay. Some Fire Marshall's (and some insurance companies) might view that as a modification of the assembly that is not acceptable)
However I do know one thing (for a fact) and that is that you can't put insulation inside of the wall cavity of any rated/tested wall assembly if the test report does not specifically indicate that you can..
There are a number of assemblies where this is the case.... the reason for that being that the rate of heat buildup inside of a wall cavity is greater (by which I mean the buildup of heat in the assembly occurs at a quicker rate) in walls with insulation than in walls without insulation........
Rated assemblies have time elements involved - and if the assembly was not tested with insulation in the cavity it might well fail at containing a fire (in the zone of interest) if this aspect of it is altered....... or even if the insulation placed within the cavity is of a different thickness or density....... so this is something you really want to look into before acting - do not assume anything.
So is there any way to do this while leaving the current firewall in tact? Is beefing up the middle layer an option, (now I just sound lazy) or would the three leaf wall be too much of a compromise? Also would I need to attach a ceiling to my new wall structure to isolate the roof?
Listen - reality is that sometimes we just have to live with the hand we're dealt..... and in instances where that is the case we look to overcome the obstacles we face....
Although the best situation would be a 2 leaf assembly - you can always leave the existing in place (with no modifications whatsoever) and overcome the situation strictly by installing additional mass on the inside face of a new isolated wall assembly........ anything can be made to work even in those cases where the starting point is not idea.....
Having said all of that my best suggestion to you would be to hire someone who knows the local codes and pay them for a consultation as to what you can/cannot do in regards to this property.... and in saying this something else comes to mind - you just said that you'll be "purchasing the bay" - this suggest to me that the property is actually a "commercial condo" - and if that is the case then you will also have to look over your condo documents......
In a typical condo the "ownership" of the property is from the "unfinished face of wall to unfinished face of wall. and the unfinished surface of floor to the unfinished surface of ceiling.
The interstitial spaces in between those surfaces and adjacent spaces, the concrete slab and the ground beneath it - and the space between the unfinished face of ceiling and the top surface of the roof are not owned by the owner of the unit but rather by the condo association - and as such you have no right (without their expressed permission) to remove anything or alter those assemblies in any manner.
So just make sure you walk through everything before you take any action whatsoever...