# Fire stopping mud



## pm_sup (Feb 19, 2007)

We've got this idiot of a CP (certified professional) who has majorlly f'd up our firestop inspection. They did not clearly specify the installation parameters and they are indicated differently on the plans. 
So the architect had passed the firestop and fire boarding/taping. The CP comes on the job site and says rip it all down.

Long story short, they have to redo their spec's. We are passing on the costs assoicated with this delay to the developer, who inturn will likely pass them on to the CP architect or both.

CP is saying there is a special type of firestopping mud available for firestopping and filling in gaps (we have nightmarish drops with tons of piped and mechaincals to deal with and piece in) so maybe using this is an option.

So have any of you used products of this type? Good, bad?
What is the tooling like? If it intersects other types of finshing mud, does it create a problem?

Thanks for any feedback.


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## Brockster (Aug 24, 2007)

I've never heard of firemud. I have had to use the red self-adhesive firetape and firecaulk from Hilti. I'd bet he is talking about the Hilti Firecaulk.

I know all too well when you have lots of penetrations it's a lot of work. Before I tore down too much I'd see the new specs for the firewall. It may be that you'll need to add pieces over the drywall you have up now around the penetrations following the spec clearances.

Oh ya, Good Luck!


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## kgphoto (May 9, 2006)

You need to give the specifics of each type of penetration and the type of wall it penetrates. Is it a membrane penetration or full? Is it a dimizing wall, or how many hour rated? Tumescent materials is probably what they are looking for. 

Rated assemblies require "rated" solutions.


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## mrp (Dec 1, 2007)

search for: USG Firecode mud

You can order a sample from the USG website.

Please let us know what you think of it if you do try it.


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## pm_sup (Feb 19, 2007)

Thanks very much for the feedback and comments.

The rated assembly was not correctly specified or reflected on the IFC (issued for construction) drawings. The architect made some mistakes and the CP did not pick them up when he stamped the drawings.

So the spec is wrong. The drywall sub-contractor quoted based on this spec, as did the general contractor (us).

It basically looks like we have to return to the, tested, rated spec for the floor ceiling, or surpass that by adding another layer of drywall.

This would not be a big deal (other than significant cost) except for the fact all the sprinkler heads are located based on the (plan spec'd) ceiling height, as are electrical boxes etc etc.

Not a nice morning, these changes are going to cost big time, probably 15-20K per floor, times 4 floors, times 3 buildings plus schedule delays. The you know what is going to hit the fan.


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## kgphoto (May 9, 2006)

Just get a RFI and see if tumescent pads will work.


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## pm_sup (Feb 19, 2007)

Thanks, I'll ask. I am not familiar with that type of installation on rated floor systems. Is it common? How is installation, easy, labour intensive?

I checked in the USG product. It looks like what will fit the requirements for wide drywall gaps. 
There was another mud suggested, I'll post here just for info. It is called Fire Halt by GP.


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## Mud Master (Feb 26, 2007)

Either will work just fine. 

I use whatever is cheaper because spec always calls for "or equivilent"...USG's was the original...GP followed, as usual.

Just make sure your sub's know how to apply it, FR mud is a lil' different than standard mud...

Good Luck!


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## oldrivers (May 6, 2007)

Its really no different than mixing bag type setting coumpound like durabond etc. usually you use it and a fire type caulking . The mud goes drywall to drywall where the caulk goes drywall to cement etc. how you apply it will vary from crack to crack because you cant always get tools inbetween pipes etc, do whatever it takes sometimes a finger is needed to apply it. 

basically all your doing is prefilling with a red colored fireproof mud and caulk.


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