- When should steel door frames be back coated for corrosion protection? I’ve seen specs that say back coat interior and exterior frames peroid, some say back coat when frames are filled w/ grout, some say only back coat when frames are filled with grout containing anti-freeze agents ( i.e.: SDI 127J).
- When should steel door frames be filled with grout? Both interior and exterior, just exterior @ cmu, just @ cmu?
We back coat all hollow metal frames with a bituminous coationg period.
We NEVER spedify backcoating on our hollow metal frames, period.
Even with asphalt emulsions you can get pin holes and rusting of the door frame. We specify galvanized exterior door frames in lieu of the coating. Galvanized frames are also cheaper than bituminous coatings.
Bituminous coatings may also void the fire rating of the door since there is a potential of the coating catching fire inside the frame.
We rarely specify grouting of door frames. Grouting does not improve the fire rating or durability. It does deading the ringing of the frame though. Where ringing is a problem we specify high density batt insulation stuffed into the frame.
The only time we specify grouting of a door frame is when the frames are installed before a masonry wall is built. That way we allow the mason to slop some grout into the frame as he builds the wall.
David
You are correct, we do specify galv metal frames, but we also add the bituminoys coating since most of our work is in Florida or the Carribean and galv. does not hold up. We have never had any problems with the fire rating, although it is a point worth looking at. Curious if any other specwriter has had that problem?
I back coat every frame, in every location, indoors and out, on every project.
In this area, its difficult to get a contractor to grout a frame unless its going into a CMU or brick wall, and you can’t get “pre-grouted” frames anymore – they were so heavy no one would handle them. The pumped grout is often so watery in order to make it pumpable, that it will separate and you end up with sludge at the bottom of the frame, and 1/3 of the frame filled with water – so that’s a bad option.
Grouting, as David said, mostly makes the frames sound less hollow, so filling them with insulation is a good option for that.
Anne,
I’m not exactly sure why you would back coat a nongrouted interior door frame?
For everyone’s consumption.
Refer to SDI 127I-04 and SDI 127J-04.
We have typ. specified backcoating all frames not fully grouted for purposes of sound control. Upon reviewing above ref. tech data, it makes more sense to fill void with insulation due to 1. It’s more effective, 2. More apt to actually be installed.
As far as galvanizing, in addition to doors in exterior walls and un conditioned spaces, we galvanize frames in basement and similar areas that might be more exposed to moisture/standing water during construction.