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').