Thread: Dwelling unit seperation

One year old townhouse. The fire-resistant wall at the dwelling seperation between units in the attic is penetrated by the following: Refrigerant lines, a 2x8 board and plastic conduit containing communication cables. These are through wall penetrations as far as I can tell.

I have read the code section addressing this several times but am still wondering about the penetrations, particularly the wood and plastic. Any thoughts?

Thanks,
Eric

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Eric,

*IF* (and it does not look like it - nothing looks 'right' about them) ... IF those penetrations where in accordance with an approved UL listed design, the refrigerant line and plastic conduit would likely be okay penetrating through the fire rated wall.

However, and this is where the above does not matter if they were okay or not, being as those at "townhouses" and not "condos", each structure should be able to stand alone (the fire rated wall between them is owned by both with the property line down the center of the wall), thus, that wood should not be going 'through' the wall. That wood could go 'to' the wall and stop at each side, but if one side burned down, the other structure should still be able to stand on its own.

Also, because these are townhouses and not condos and the center of that fire rated wall is the property line, *nothing* from one unit should go through the other unit, least the owner of one unit go up there and tap off / cut / remove / damage / whatever goes through their unit.

Also, I see no fire protection for the roof sheathing extending out 4 feet, is there a 30" high parapet wall at that fire rated wall penetrating up through the roof and 30" above the roof? Should be, or that roof sheathing needs to be protected for at least 4 feet out from each side of the wall (an 8 foot piece is too short as you do not measure from the center of the wall, from each side of the wall).

This unit is only a year old so I would check with local building authority and check the plans to see what the rating is for this wall Find out the hour rating 1 2 or 3 hour rating? This rating will determine what type of material you will need to fill these penetrations. These need to be taken care of as they do nullify your fire protection and energy consumption.

Originally Posted by Jerry Peck

Also, I see no fire protection for the roof sheathing extending out 4 feet, is there a 30" high parapet wall at that fire rated wall penetrating up through the roof and 30" above the roof? Should be, or that roof sheathing needs to be protected for at least 4 feet out from each side of the wall (an 8 foot piece is too short as you do not measure from the center of the wall, from each side of the wall).

Thanks Jerry,

It did not appear that the annular spaces around the pentrations were fire sealed. Also, it turns out that the HVAC contractors originally connected the refrigerant pipes to the neighbors evaporator unit and vice-versa, so I am assuming that they re-routed the lines through the wall when they did the repair, after the construction of the wall.

There was no parapet wall and I did mention that there was no fire protection at the roof sheathing.

I have another question about this area of the code. Although we are on the IRC 2000 in my area, I am quoting from the 2003 IRC (because it's on this computer and easier to copy and paste than type out the 2000): (Bold, of course, is mine)



R317.3.

317.2.1 Continuity.
The common wall for townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab and shall extend the full length of the common wall including walls extending through and separating attached accessory structures.

317.2.2 Parapets.
Parapets constructed in accordance with Section R317.2.3 shall be provided for townhouses as an extension of common exterior or walls in accordance with the following:
1. Where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces.
2. Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches (762 mm) above the lower roof, the parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.
Exception: A parapet is not required in the two cases above when the roof is covered with a minimum class C roof covering, and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) Type X gypsum board is installed directly beneath the roof decking or sheathing for a distance of 4 feet (1219 mm) on each side of the wall or walls.
3. A parapet is not required where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is more than 30 inches (762 mm) above the lower roof. The common wall construction from the lower roof to the underside of the higher roof deck shall not have less than a 1-hour fire-resistive rating. The wall shall be rated for exposure from both sides.


If the roof surfaces are at different elevations (greater than 30 inches) and the wall's fire resistance is in place in accordance with the bold section above and a parapet wall is not required, would this also mean that since the parapet is not required, the deck sheathing protection would also not be required?

Also, when it states the wall shall be rated for exposure at both sides, what type of exposure is it referring to?

Thanks,

Eric

I would list my findings and recommend having the applicable City building inspector and original contractor (builder) evlaute and advise on this.









Rolland Pruner

Originally Posted by Eric Shuman

3. A parapet is not required where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is more than 30 inches (762 mm) above the lower roof. The common wall construction from the lower roof to the underside of the higher roof deck shall not have less than a 1-hour fire-resistive rating. The wall shall be rated for exposure from both sides.

If the roof surfaces are at different elevations (greater than 30 inches) and the wall's fire resistance is in place in accordance with the bold section above and a parapet wall is not required, would this also mean that since the parapet is not required, the deck sheathing protection would also not be required?

Yes.

When there is a 30" height difference in the roofs, say one unit is a one story and the adjacent unit is a two story (just an example) then no parapet wall is required (it is already there as the wall extending up to the higher roof) and no protection of the roof decking is required (because that wall serves the same function as a parapet wall - provided that the wall is fire rated.

Also, when it states the wall shall be rated for exposure at both sides, what type of exposure is it referring to?

That is referring to exposure to fire from both side.

A fire rated wall needs to provide protection to either side from a fire originating on other side of the wall.

Also, it turns out that the HVAC contractors originally connected the refrigerant pipes to the neighbors evaporator unit and vice-versa, so I am assuming that they re-routed the lines through the wall when they did the repair, after the construction of the wall.

What they should have done was to cut the refrigerant lines and properly reconnect them on the proper side of the wall, without penetrating the wall, this would effectively 'swap condenser units' between the townhouses, which is what it sounds like was needed.

Or, if one condenser unit was larger than the other, then they should have left the refrigerant lines run as was and swapped the condenser units around (making any and all refrigerant piping and electrical wiring changes needed, if any were needed.

Instead, they screwed things up even more by trying to take the easy way out.

In condos, you can do that as the structure is 'one' structure, but in townhouses each unit is a 'separate' structure and should be able to stand alone (so to speak, given that they are 'attached').

Jerry
does this apply here as well
**Also, I see no fire protection for the roof sheathing extending out 4 feet, is there a 30" high parapet wall at that fire rated wall penetrating up through the roof and 30" above the roof? Should be, or that roof sheathing needs to be protected for at least 4 feet out from each side of the wall (an 8 foot piece is too short as you do not measure from the center of the wall, from each side of the wall).**

This is a 1982 home. I guess these are row houses. 2 higher end homes butted together on the beach, cmu walls do not extend to roof. there obviously never was any sheathing protection and i do not see it on the older homes i inspect in this area, but the newer ones do?

1982? May or may not have been in the code, however, that said ...

... Fires cannot read code to see if they are allowed or not.

Yes, if that wall is the fire separation wall between the homes (referred as "townhouses" regardless of their size or price if there are more than two, if only two they are referred to as two-family dwellings, or ... gulp ... duplexes ).

That fire separation wall should be fire caulked along the roof sheathing and around all of the trusses, the roof sheathing should be protected for 4 feet out from the wall - measured from each side, there should not be any penetrations through that wall from dwelling to dwelling, that gypsum board should be 5/8" Type X.

Now, acknowledging that they are not going to replace the gypsum board nor install new gypsum board over it if not Type X, you should still them 'it should be 5/8" Type X for fire protection'. Your client needs to know and you need to tell them (to keep their lawyer at bay so he does not come a calling on you after a fire, especially being as this is "high end").

Normally, it is not too difficult to protect the underside of the roof sheathing with Type X gypsum board after-the-fact like in that case, however, being as they used 16d nails for roofing nails - that's going to make it difficult to install the gypsum board up against the roof sheathing, so ...

... the easy solution is to now install the gypsum board on the underside of the top chords of the trusses.

Of course, though, I would also tell them that, when their neighbors unit burns down, the other half of the trusses (which are over their neighbors unit) are going to burn and their half of the trusses are not design to be 'free standing without support on the other side', i.e, there is a good chance of losing their unit due to a fire in the adjacent unit.

I might even humorously (and mean it, just say it that way) suggest that they put a smoke detector in their neighbors attic and wire it to their system, such that when a fire does occur 'over there' that *they* have time to react 'over here' and GET OUT!

While it is not much fun to watch your house burn down, it is even less 'fun' to watch that while you are *still in it*.