[collyn]

Hi everyone, I have a question on fire rating.

I am converting a home built in 1914 from a 2 story 1 family unit into 2 units. One upstairs and one downstairs. TRhe lower floor is finished and the upper floor is where we will be doing working.

By code, I will have to fire rate between the two units.

Typically, I would put two layers of 5/8s drywall on the ceiling of the the lower unit, but that is where I run into the problem.

The celings are covered in decorative moldings, not just at the top of the wall where the crown is, but throughout the ceiling, making it an extremely difficult and cost prohibitive solution.

I have wood floors above, I am wondering if anyone knows of a way to fire from the floors above?

I would be willing to remove the wood floors, apply a solution with the fire rating and then re-install them, but I do not know of a solution that would give me the 2 hour rating that a require.

Does any one know of a solution?

 

[JobSuper7]

Good question all I can think of is if your willing to demo the flooring they do make fire treated plywood you could install and then fire caulk the seams and walls and rock wool other voids you may come across but that could very costly. But what I would do first is compare the cost to sprinkler the building vs the fire treated lumber. Is this an insurance requirement? Or is the building department or fire dept requiring you to do this?

 

[JobSuper7]

Good question all I can think of is if your willing to demo the flooring they do make fire treated plywood you could install and then fire caulk the seams and walls and rock wool other voids you may come across but that could very costly. But what I would do first is compare the cost to sprinkler the building vs the fire treated lumber.

 

[collyn]

Thanks super7, so the sprinkler system could possibly negate the need for Fire Rating?

 

[iDAHOchris]

Would Gypcrete work?

 

[hdavis]

Hi everyone, I have a question on fire rating.

I am converting a home built in 1914 from a 2 story 1 family unit into 2 units. One upstairs and one downstairs. TRhe lower floor is finished and the upper floor is where we will be doing working.

By code, I will have to fire rate between the two units.

Typically, I would put two layers of 5/8s drywall on the ceiling of the the lower unit, but that is where I run into the problem.

The celings are covered in decorative moldings, not just at the top of the wall where the crown is, but throughout the ceiling, making it an extremely difficult and cost prohibitive solution.

I have wood floors above, I am wondering if anyone knows of a way to fire from the floors above?

I would be willing to remove the wood floors, apply a solution with the fire rating and then re-install them, but I do not know of a solution that would give me the 2 hour rating that a require.

Does any one know of a solution?

Something like this, perhaps:

http://shieldindustries.com/fireguard_wp/fireguard/fireguard-e-84/

 

[Tom M]

You need a "fire barrier" to protect the floor from the flames below. Protection from the top side will not offer protection to the structure from below.

 

[mikecocozza]

Good question all I can think of is if your willing to demo the flooring they do make fire treated plywood you could install and then fire caulk the seams and walls and rock wool other voids you may come across but that could very costly. But what I would do first is compare the cost to sprinkler the building vs the fire treated lumber. Is this an insurance requirement? Or is the building department or fire dept requiring you to do this?

Typically sprinklers do not negate the need for rated assemblies. In some instances it will allow for an assembly to go from say a 2 hour required wall to a 1 hour required wall.

 

[hdavis]

Good question all I can think of is if your willing to demo the flooring they do make fire treated plywood you could install and then fire caulk the seams and walls and rock wool other voids you may come across but that could very costly. But what I would do first is compare the cost to sprinkler the building vs the fire treated lumber. Is this an insurance requirement? Or is the building department or fire dept requiring you to do this?

Conversion of use, so it isn't grandfathered, it has to meet current code, including NFPA Life Safety 101.

Putting fire rated sheathing on the floor won't get you a rated assembly - the problem here is the joists have to be protected from a fire on the lower floor. Easy to do, as long as you tear out the decorative plaster work.

Requirements for sprinkling vs fire rated construction vary by jurisdiction, and the insurance company may have their own ideas.

 

[hdavis]

As a side note, putting in a sprinkler system will either result in ugly pipes obscuring some of that decorative plaster, or the plaster is going to get all chopped up for the install. It's an expensive proposition and is going to detract from what's there right now.

 

[Anti-wingnut]

As a side note, putting in a sprinkler system will either result in ugly pipes obscuring some of that decorative plaster, or the plaster is going to get all chopped up for the install. It's an expensive proposition and is going to detract from what's there right now.

He said he's willing to rip up the floors above

 

[hdavis]

He said he's willing to rip up the floors above

Then there will only be a few holes in the plaster. Honestly, being able to use PEX now makes it tons easier to sprinkle than it used to be. Unfortunately, my recollection is the code trade off with sprinkling is not the fire rating, it's the egress requirements.

 

[hdavis]

He said he's willing to rip up the floors above

Good thing, he'll probably have to to get a continuous barrier, or at least pull it up in areas to seal penetrations.

 

[griz]

The main reasons for having fire rated assemblies is to stop/slow the spread of flame, contain it in an area and protect structural members.

If some manner of fire rated assembly is installed from above it seems that it will be rather difficult to protect any structural members in the floor system. If the floor joists or any structural members of the floor system were to collapse from flame below, the fire would no longer be stopped/slowed or contained.

 

[overanalyze]

The main reasons for having fire rated assemblies is to stop/slow the spread of flame, contain it in an area and protect structural members.

If some manner of fire rated assembly is installed from above it seems that it will be rather difficult to protect any structural members in the floor system. If the floor joists or any structural members of the floor system were to collapse from flame below, the fire would no longer be stopped/slowed or contained.

Very sound advice. Check with your local building dept. on what they want to see. It's tye safest way to proceed.

 

[Anti-wingnut]

The main reasons for having fire rated assemblies is to stop/slow the spread of flame, contain it in an area and protect structural members.

If some manner of fire rated assembly is installed from above it seems that it will be rather difficult to protect any structural members in the floor system. If the floor joists or any structural members of the floor system were to collapse from flame below, the fire would no longer be stopped/slowed or contained.

You're right. If the OP looks in the USG book he'll get a good idea about fire rated assemblies.

The joists must be protected, and I don't see how that can be done from above. Fire treated wood isn't made as a substitute for Type X GWB, it is meant to supplement the GWB and result in a slightly higher rating than with normal framing lumber.

Now a smart archy might be able to find a way for springs to give you the protection you need, because in a duplex the rating is all about egress. In fact, almost all fire rating is about being able to get the peeps out.

 

[CarpenterSFO]

You could see if these people have anything to offer:

http://www.firefree.com/fire-retardant-products/ff88-intumescent-coating.php

Their literature talks about historic renovations, etc.

The question, as always, is what's your budget?

 

[hdavis]

These intumescent coatings are attractive for these types of situation - I don't see a better way to go, and sprinkling won't negate the need to have a fire rated assembly around here.

 

[Tom M]

Good Link Bob, have tot remember this product exists.

 

[JobSuper7]

I don't know if a coating would be the answer for this paticular application either, it could find some voids in the floor assembly and ruin the decorative ceiling on the first floor too. Like it was said earlier in the thread check with the building dept and let them tell you some acceptable options then decide.
To all the people against sprinklers to solve Collins problem explain to me why fire depts. across the country pushed for them to be in the ICC debate if they don't negate the rating? The knob and tube that is most likely in the wall cavity most likely isn't fire caulked either so a flame will find a way to spread in a house built in 1914. Fire dept know this and feel safer going into a burning house knowing that it's sprinklered. I've served on couple different code councils and the fire dept representatives have repeatedly pushed for sprinklers. I don't like them anymore than the next guy because it adds a lot of cost to the job but on the other side of the coin it could cost a life!