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Commercial Questions-- Doctors office


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I'm a newbie when it comes to doing commercial inspections, so please school me.

The building I inspected is in a professional center, and if it were a residential house, I'd consider it to be a duplex (1 building,2 separate offices/ owners).

The building was constructed in 1980 and is a single level structure with a sloped roof and crawlspace.

There is a history of conversions and remodels inside of the structure as uses / needs changed.

QUESTION#1:

The DWV system was originally all cast, and now there is quite a bit of ABS tied into it. Is there a reason/ requirement for the DWV pipes to all be cast?

QUESTION #2:

There are 2 layers of 5/8" type X drywall installed between units in the attic, and in the crawlspace cripple wall.

The seams were not taped/ sealed-- is this a problem?

The drywall has since been penetrated by ABS DWV pipes (both in the crawlspace and attic)-- is ABS pipe allowed to penetrate a firewall?

QUESTION #3 not limited to commercial:

This is the second crawlspace I've seen in the last couple of weeks that lacks any form of ventilation (60's and now 80's built). It's not a plenum crawlspace, doesn't have any crawlspace vents, nor is there any dehumidifier system in place. Basically, the stem walls are all insulated, and pea gravel is installed on top of a poorly detailed vapor barrier. I must assume that this used to be allowed. Anyone know the history of code changes that now prevent this design?

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I'm a newbie when it comes to doing commercial inspections, so please school me.

The building I inspected is in a professional center, and if it were a residential house, I'd consider it to be a duplex (1 building,2 separate offices/ owners).

The building was constructed in 1980 and is a single level structure with a sloped roof and crawlspace.

There is a history of conversions and remodels inside of the structure as uses / needs changed.

QUESTION#1:

The DWV system was originally all cast, and now there is quite a bit of ABS tied into it. Is there a reason/ requirement for the DWV pipes to all be cast?

Aside from the fire wall issue, below, I don't know of a problem with it. Cast iron is quieter.

QUESTION #2:

There are 2 layers of 5/8" type X drywall installed between units in the attic, and in the crawlspace cripple wall.

The seams were not taped/ sealed-- is this a problem?

There are many different kinds of fire rated assemblies. Some require tape & joint compound at the seams and some don't. I'm not well versed in them all, but my hunch is that the only way you'd know for sure is to get ahold of the original plans & specs.

Personally, I wouldn't mention it. If you wanted to be conservative, I'd say something like, "On the firewalls in the attic and crawlspace, the outer face joints are exposed. If you'd like greater protection against the spread of fire, hire a drywall finishing contractor to apply paper tape and drywall compound to all of the exposed drywall joints."

The drywall has since been penetrated by ABS DWV pipes (both in the crawlspace and attic)-- is ABS pipe allowed to penetrate a firewall?

As far as I'm aware, plastic pipes & conduits aren't supposed to pass through rated fire walls. That said, I've seen it done and approved where intumescent collars were used. But I can't find a reference that alllows it.

QUESTION #3 not limited to commercial:

This is the second crawlspace I've seen in the last couple of weeks that lacks any form of ventilation (60's and now 80's built). It's not a plenum crawlspace, doesn't have any crawlspace vents, nor is there any dehumidifier system in place. Basically, the stem walls are all insulated, and pea gravel is installed on top of a poorly detailed vapor barrier. I must assume that this used to be allowed. Anyone know the history of code changes that now prevent this design?

The only time I've seen that done is when the crawlspace is intended to function as a plenum. Are you sure it wasn't a plenum space at one time?

- Jim Katen, Oregon

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As the uses of these two occupancies were changing and the building was being remuddled, permits & inspections should have been required and obviously did not occur. It's a bit difficult to say just exactly what should be there without a set of plans and without knowing the occupancy category of each side, though you definitely described enough to indicate that a few things are a problem.

The required fire rating of the separation walls will depend upon the occupancy and upon whether they are load-bearing. In general, I agree with Gary about the taping. It is not something I would care about in a house, on something like the separation of an attached garage. A commercial building is different. Systems with 2 layers of 5/8 Type X each side are typically 2-hour walls, and would be constructed either to the specs in the Gypsum Association's Fire-Resistive Design Manual or to chapter 7 of the building code. The assumption in the GA Manual is that you will tape the surface layer, though there might be some systems with steel studs that don't require it.

The plastic pipe penetrations are a bigger problem. While it is cheaper and easier to work with than cast iron, the savings is more than offset by the much greater cost of proper firestop penetration systems when going through the rated wall. Penetrations for cast iron can be handled by filling the annular space around the pipe with equivalent non-combustible material to the rating of the wall. With plastic you are only going to salvage it with a listed firestop penetration system.

I'm surprised to hear of an unvented crawl on something that old. They are all the rage now.

You are swimming in the deep end of the pool, and there are a lot of dangers to broaching these issues. I think the red flag should simply be that there appear to be code compliance problems with the fire separations, such as - and then list what you saw. If I were the client, I would want the plans and I would take them with your report to the local building department. Of course, your client might be different. They might decide that is the last thing in the world they want to do.

Douglas Hansen

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The only time I've seen that done is when the crawlspace is intended to function as a plenum. Are you sure it wasn't a plenum space at one time?

100%99% positive.

The building is located directly across from the old hospital in Newberg-- you probably know the medical professional offices I am referring to.

The building has a package unit heat pump that is original. Plywood return air plenum in the crawlspace, with jumper ducts in each room/ office. All forced air ducts are GSM. (all original looking).

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Interesting questions. I'm not much help because we can't build anything in Chicago in the manner you described.

The only things that jumped out at me are the plastic pipe penetrations and the ancient package HVAC.

One thing I've learned about rooftop package systems in Chicago; they're good for about 15-18 years, and then they're maintenance hogs or fail completely.

I'd be schooling myself @ the local buildings dept. to answer most of those questions.

Good for you for jumping in; I did several of these that, in all honesty, I didn't make any money on other than having my education paid for. I spent as much time researching these sorts of questions as I did doing the inspections.

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One thing I've learned about rooftop package systems in Chicago; they're good for about 15-18 years, and then they're maintenance hogs or fail completely.

I subbed out the HVAC system. I've only run into one package heat pump and figured I'd learn something by having someone else come in.

This ground unit was sitting well out of level. When I asked the tech. whether he would recommend leveling it, he said " it's working the way it sits, and something will probably break if we mess with it"

He also said their typical life expectancy is 15 years, but he's seen some of them go 50-- quite the variance.

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Thanks Mike,

I don't think I've ever seen anything like it before.

Arbor used them in a few houses up in the Bethany area.

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Of course, that's not a fire-rated ceiling assembly.

I'm still unable to find anything that allows plastic pipe to run through a fire rated wall, even with the intumescent collars. It's probably a local AHJ call.

Whether or not the walls in your pictures were constructed properly is moot at this point. They've been hacked up enough to merit serious repair.

- Jim Katen, Oregon

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Here's some pictures of the penetrations.

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I've never seen joists penetrate a firewall. They're not supposed to. Makes me wonder if this construction was really installed to mitigate sound transmission between the two adjacent office condos.

Marc

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Here's another issue I ran into.

This steel support column's flange/ plate? didn't quite make it to the pad.

The contractor figured out an ingenious way to address this issue.......

I'm sure it's just as sound this way.

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It's a leveling method (to make the column plumb) Look at your street light and traffic light bases. Same theory.

Allows for fine adjustment to ensure the column is plumb.

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Yes and it works fine there, but a column that is supporting structure needs to be grouted when it is placed like that. At least they did here in the 90's.

I figured as much, but don't run into steel column's very often. Nothing like pouring a large pad, using a large steel plate, and then relying on a few threads for compressive strength.

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