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Fire Blocking - 100 year old gutted home

11154 Views 13 Replies 8 Participants Last post by  tracibuck
Hello and good morning! I saw a thread on fire blocking on here and just want to be clear on what I will be required to do. I have had some minor difficulty in getting in touch and communicating with the permits office as we are in a small township in NJ and the inspector is only there for about 8 hrs. a week. So I am hoping that you guys can provide some clarity.

My house is a ballon construction home where I can see from the third floor attic to the basement foundation. I have the home gutted and am currently beggining the wiring process but the blocking is holding me up a bit. The first picture I have is on my first floor looking up towards the second story, as is the second picture with a bit of a steeper view up towards the second story/attic. What is the proper way to fire block this? Will this be required under building code to do? I am adding insulation (fiberglass batt) on all levels. Any advice on this subject would be greatly appreciated, from the required code to the easiest and most efficient way to do this in my 100 year old home.

Thanks and let me know if there is anything further I can provide to clear it up at all.



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#1 You need to go back and add your location to your profile, Yes it make a differance where you live.

Here the way I do it, I add solid wood 2X's at the top and bottom of the walls. Any place there's gaps or a notch where a wire goes get filled in with high heat caulking for the small gaps, and expanding high heat foam on the big gaps.
I also add blocking along the middle of the wall.
Those old 2X's are going to be wider then a new 2X so your going to have to rip 2 X 6's or just add whatever thickness spacer you need.

A few things to concider.
Adding house wrap (Tyvek) between the wall studs to cut down on the drafts.
Getting rid of all that old steel pipe before it starts leaking.
Building the studs out so you can fit more insulation.

The very best way if you can afford it is to use foam not batts.
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Boy does this bring back memories! I always wondered about the guys that hand nailed all that plaster lath in place, man what a PIA, Huh? Here are a few things you are going to run in to. Studs out of alignment. They put that lath on and trued up the walls with brown coat. I bet yours had horse hair in it right? I had to sister 2x6's to some walls they were so far out, and used string lines for plumb.

Joe is correct re the piping, get it out NOW. In NJ in a lot of towns you have to use copper. Use min type L. Not M.

As far as the fire stopping, make sure you talk to the BI, and do what they say. many of the small towns in NJ have their own rules, and its easier to comply than try to buck. I would use fiberglass Bat, if I were you, and a poly vapor retarder on the studs, under the drywall, this will help a lot with drafts and moisture migration. When foam burns it produces cyanide gas and will kill you fast. It can also leach chemicals for years, and cause all kinds of allergic reactions. Watch out for Asbestos, You will probably run into it somewhere. If you do, PM me and I will help you be rid of it safely.

Hopefully you have a nice table saw to rip with. Good luck.
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In taking apart this house I wonder about a lot of things, mostly how it is still standing! Now that everything is out I believe that I am going to start a project showroom peice to keep everyone updated and so that I can get advice regularly.

Thanks for the responses. The walls are suprising true, but i am sure that i will need to true them up at some points. The Piping is actually unconnected old gas lighting piping (small piping).

The other two pipes are radiator piping and are being moved as that exterior wall is coming down. I will have a plumber do this so whatever he puts in has to meet code so we will see. I will be taking out a bunch of walls so I will have some "real" 2x4's to work with when blocking. I know that the blocking will help to some degree, but this whole house is made of 100 year old dried wood, basically kindling so I feel like this will be a wasted effort. I guess whatever code is I will certainly have to meet it.

You dont happen to be/or know any good insulation guys in the Haddonfield area do you? I need some spray foam done in a particular area of the house to try to get my R-30 in a ceiling that I do not want to build out too much.
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Again, I would not use spray foam, but that is up to you. I know a lot of people that were very sorry they did it though due to fumes mold etc. Most of the walls in these old houses were load bearing so be careful. You are removing a hell of a lot of weight with the plaster and lath all going though.
Amazing you have gas supply for lighting. No knob and tube? Was the trim Chestnut? I hope you saved that.
All of the above. Already removed all the knob and tube (5 out of 12 circuits). Removed all of the trim (to be put back up later). Also have had structural engineer in for my structural work. We have to 1) jack up the house and resupport the main center beam 2) reinforce by sistering the 1st floor main beam to hold up the 2nd and 3rd floor (currently 2- 2x 6's). We are taking out the old exterior of the home to open it up into the kitchen and den. (about 18ft of the old exterior). And finally we have to build a new header where they just notched studs of the old exterior for the new and improved entranceway. They also notched all the old floor joists in the 2nd floor for plumbing so we have to remove the plumbing and rebuild that. All of which I have sketches for. Should make for a fun Christmas break.

The only reason i may need to put in foam in a small section of the house (kitchen addition) is b/c the rafters are 2x4's. It is a vaulted ceiling going from about 12ft down to 8. If i build up the rafters I may be looking at to low of ceilings at the 8ft end. Cabinets will be here so I really do need all 8 ft. of ceiling. Everywhere else in the house will be batt insulation as I have adequate space. Not as much as I would like but enough to meet code.
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Sounds like you have it together, my friend. Good Luck, and happy Holidays.

PS While you have those walls open you might want to put in a couple of 2 inch PVC Pipes from basement to attic for wire chases. Just a thought. :wink:
Haha...that is the only part I have together! I need to complete all constructuion before really doing anything else and putting anything back in. Going to be a long process. And thanks for the advice, never really crossed my mind to put chases in.

Merry Christmas.
Fire blocking is a barrier. An outlet fire from first floor can burn its way to second without something blocking the path, especially in a balloon frame house. It's every vertical 8 feet, and houses with 8 foot ceiling has top plates that are natural blocks. Yours should have 2x4 blocks just even with the bottom of the second floor joists. Use mineral wool batts to fill the second floor joist bays. Same for basement and attic. You should have some 1x blocking along the second floor as nailers for trims.
Tyvek is not a draft barrier. Tape is used to batten down the exterior, but I don't trust these tapes. For one thing, warranty on these tapes is 10 years only. Cellulose stops draft, but is vulnerable to water leaks. You can spray foam the joints in the t&g sheathing and along the studs and sills. Buy bulk. Or fit 1/2" foam sheet between the studs and install r13 fiberglass. Little compression doesn't affect the r value, but draft will.
Then, what is it?
it is a weather barrier .... keeps moisture from the exterior of the wall from migrating inside the wall, and allows any trapped vapor within the wall to escape

the 2009 International Residential Code is the basis of most local building codes. This link will provide you with code requirements as to location and materials fire blocking is to be constructed from.

you would need to verify with your local building official if the 2009 IRC is the basis of your building code.

Happy Holidays
Might want to give DuPont a call and let them know that all these years they have been misleading the public then.
It's moisture and air barrier.

I even made a sail out of it for a tiny sail boat one time.
Tyvek…a “moister vapor” barrier maybe. If the gets wet often enough it won’t be a barrier for long.

A regional opinion I guess. :whistling2:
So what did you end up doing?

We are at the exact same point you were when you posted, what did you end up doing and did it work? Any pictures?
Thanks for any input.
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