We are getting a number of requests from Architects to remove the requirement for bituminous coatings at hollow metal door frames. I’m not sure they know what it is for. It seems to me, that it’s the right thing to do, and we should require it as our default position. Are you all still requiring this?
I still require bituminous coating in HM frames, but only for those filled w/ grout containing antifreeze agents (per MasterSpec).
Same as Jeffrey with the addition of installation in concrete or block walls.
I agree with Lynn.
I still require it for frames in conc or masonry
I agree with you Lisa, especially at masonry openings. at interior partition (wood or metal frame) it’s not as necessary but helps with sound transfer where needed.
Read SDI 127J-04 in their Technical Data Series Industry Alert.
We require a coating in the same locations as noted by everyone else so far on this thread … however we have changed the type of coating. We found that the product we previously specified did not meet the low VOC threshold required in order to achieve the low VOC LEED credit.
So what did you change to? (cute picture!)
SDI 127J-04 states the modern replacement material for bituminous back-coating is automotive undercoating.
It also says back-coating shall not be installed at the factory or any other location other than the jobsite.
Yeah, that’s what I’ve changed to, but I wondered if Tracy had something different…
From an undercoating ad; Valid?
There are several kinds of undercoating compounds available for use in the automotive industry such as a water based, paraffin based, petroleum based, rubber based or asphalt based material. An asphalt based compound, however, provides superior coverage and protection and is made with special fibers and fillers that not only make it more abrasion resistant than other undercoating materials, but also provides excellent insulating qualities, road noise reduction and durability.
A clean, dry surface is necessary to achieve a through bonding of the asphalt compound to the undercarriage. Applied with a high pressure, airless pump the asphalt undercoating material is then sprayed to all areas.
The asphalt material that is used exceeds Federal Specification TT-C-520b for 1,000 hours salt spray, and acts as an excellent rust inhibitor for the undercarriage components. Second, the density of the compound not only reduces the amount of noise, but also acts as an insulator to help maintain the interior climate. Finally, the outstanding durability of the asphalt based undercoating is long lasting.
Thank you all for your (as always) insightful responses.
Does anyone, perhaps from construction administration, have an actual product name for this automotive undercoating, which meets LEED VOC standards? I’m assuming this is just typically done, but no product data is submitted for LEED.
Remember the purpose of the LEED credit you are referring to is “Indoor air Quality”. If the coating is applied in the shop where the VOC off gasing is controlled, then this coating is not even looked at. This credit only applies to field installed coatings. Specifying it to be shop applied meets the intent of the credit (which is to protect people from the off gasing).
Russ,
SDI 127J-04 states “back-coating shall not be installed at the factory or any other location other than the jobsite.”
Bingo! VOCs are now in play.
Just curious, but why would that be?
LEED does not address this type of “coating.” And if it did, the VOC content would be much lower than what SCAQMD allows (which is what LEED relies on in establishing the VOC limits for paints and coatings).
AND… Even if for some reason the VOC content was outside the limit, and LEED did address it, applying coatings in the “shop” would satisfy the requirement. As long as the coating is not applied within the project interior space, there is no issue.
SDI says this so they and their distributors can weasel out of having to do it–it’s awfully inconvenient, no? Now it’s some jobsite worker, and the manufacturer and distributor can go home fat and happy. Thank goodness contract documents take precedence over self-serving standards. I once asked a manufacturer about putting a sound-damping material–like used on automobile sheetmetal or the bottom of a sink–to reduce the ‘tinniness’ of wide-throat frames. You’d have thought I asked them to make the frames out of hammered copper–simply impossible.
Thank you all for your help with this. We will continue to require this field-applied coating for metal frames at concrete and masonry partitions. I agree that this type of coating is not addressed by LEED credits and requirements.
I work for door/frame/hardware supplier.
We use an auto undercoating material from 3M. We use 3M Undercoating Black 08881 to “back coat” our frames. 3M claims it provides corrision protection and sound deadening.
The material comes in an aerosol can.
Most of the time, the specs I see, don’t specifically tell you what the “back coating” material is. Just that it is to be applied.
If we see “back coating” in the spec, we put it in our price apply the material in our shop even if the specs say field apply. The contractors don’t want to apply it in the field. They expect it to be done in the shop.
Don’t worry about the “back coating” being compromised during shipping. Once it is applied, it is almost impossible to remove without sanding, scrapping, or applying chemicals.
I’m glad to read about this undercoating product, and that there is at least one supplier (somewhere) willing to do it. That gives me some assurance that this is feasible. I’m going to update our office master to include this product for use in particular conditions: grouted frames and wide throat frames. Of course there’s a cost to it, but it’s worth it. If you know of other equal products, can you post them? Thanks.