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anon (Unregistered Guest)
Unregistered guest
Posted on Wednesday, July 27, 2011 - 01:49 pm:   Edit PostDelete PostPrint Post

Aside from aesthetics, is there any reason not to accept knocked-down HM door frames over welded for interior doors?
Lynn Javoroski CSI CCS LEEDģ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 1281
Registered: 07-2002


Posted on Wednesday, July 27, 2011 - 05:03 pm:   Edit PostDelete PostPrint Post

What kind of facility is it?
Wayne Yancey
Senior Member
Username: wayne_yancey

Post Number: 478
Registered: 01-2008


Posted on Wednesday, July 27, 2011 - 05:15 pm:   Edit PostDelete PostPrint Post

David,

Typically, knock-down in gypsum board/steel stud partitions, when the partition is erected before frames arrive on site and frames are installed later. Frames in gypsum board/steel stud partitions wrap the head and jambs making it impractical to install a welded frame 40" wide in a rough opening 39" wide. SDI installation guides show installation methods in wood and steel stud walls for both welded and knock-down frames. Both with frames before and after framing.

Welded when installed in a prepared rough opening 3/8 to 1/2 inch wider than frame (concrete or CMU are two examples). Welded is also used when the frame is placed for building into a CMU wall.
Lynn Javoroski CSI CCS LEEDģ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 1282
Registered: 07-2002


Posted on Wednesday, July 27, 2011 - 05:27 pm:   Edit PostDelete PostPrint Post

For most of our projects, in labs, medical facilities, and higher ed, we specify fully welded unless it's in an in-place gypsum board partition. It's for strength and sanitation.
Richard L Matteo, AIA, CSI, CCS
Senior Member
Username: rlmat

Post Number: 429
Registered: 10-2003
Posted on Wednesday, July 27, 2011 - 05:40 pm:   Edit PostDelete PostPrint Post

I never specify or accept knock-down frames for new construction.
If the contractor erects the gypsum board walls before receiving the frames - gee, that too bad. The only time I allow knock-down frames is in renovations where the gypsum board walls are already in place.
David Axt, AIA, CCS, CSI
Senior Member
Username: david_axt

Post Number: 1222
Registered: 03-2002


Posted on Wednesday, July 27, 2011 - 05:48 pm:   Edit PostDelete PostPrint Post

Knock down frames have the following disadvantages:

KD frames take longer to install because there are 3 pieces instead of 1 piece welded frame.

KD frames are only rated up to 90 minutes. You can't get a 3 hour rating.

KD frames are only as strong as the stud wall. Welded frames are stronger than the stud wall.
Ronald L. Geren, AIA, CSI, CCS, CCCA, SCIP
Senior Member
Username: specman

Post Number: 961
Registered: 03-2003


Posted on Wednesday, July 27, 2011 - 05:58 pm:   Edit PostDelete PostPrint Post

As a side note, if you want a welded frame look for an existing opening, take a look at ASSA ABLOY's "ReadySet" system. It's a pre-hung door with all hardware installed and the frame is a two-piece unit--one for each side of the wall.
Ron Geren, AIA, CSI, CCS, CCCA, SCIP
www.specsandcodes.com
Beth Stroshane
Member
Username: beth_stroshane

Post Number: 3
Registered: 10-2005
Posted on Wednesday, July 27, 2011 - 07:29 pm:   Edit PostDelete PostPrint Post

Better and Worse depends on which seat you are sitting in and which day it is. I had a similar question at the office and following a bit of research I compiled the following summary:
Iíve heard from many Architects that they donít like how knock down hollow metal frames look and sound. (you can see a corner joint line on the face of the frame). The fear is that the contractor will make us do it because they are cheaper.
This made me question how much cheaper? Why havenít I ever seen an entire job switched to knock down frames, when Iíve seen many jobs stripped of epoxy grout? Are they inferior? How have Architects won this aesthetic battle when they have lost so many others?
According to my favorite door frame rep we have the following break down for a 16 gage, A250.8, Level 1, Prime painted 7-3 door, and they perform the same in testing:
ē Knock down frame - $125
ē Face welded frame - $165
ē Fully welded frame - $205
At this point Iím feeling like Iíve hit the VE jack-pot, at $80/frame we can save $16k on 200 doors. A joint line is not that offensive, aluminum and wood frames have the same joint line.
Then I made my second call, to a contractor friend who was buying out a door package the same week. I told him what I discovered and asked him, for that kind of money why are we not being pressured to switch to knock down frames? He didnít know, but the crusty superintendent sitting next to him did, and his bid prices confirmed.
The contractor has to assemble the frames in the field, so the $80/frame is eaten by increased field labor cost. With field labor added in it is really $7/frame savings. The installing contractor usually has to fix a couple double door frames on a job because it is a challenge to get them perfect, and they have to be perfect for heavy double doors to not swing out of tolerance.
My $16,000 dollar savings has shrunk to $1400 and that doesnít cover the price of one call back. As an added comfort, general contractors regularly self-perform doors and frames and the pain of door call backs is very close to home.
If you run into a general contractor who doesnít have a superintendent to set them straight just have them price it both ways and donít forget to include the field install labor.
Lucky for Architects everywhere; money is protecting us from the unsightly crack and cheap sounding hollow sound in knock-down metal door frames.
Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2

Post Number: 288
Registered: 12-2006


Posted on Wednesday, July 27, 2011 - 07:48 pm:   Edit PostDelete PostPrint Post

Beth,

Thank you for walking us through the real world cost differences when you include labor. Desigers and specifiers tend to think that simpler is cheaper when it is often not. My favorite example was a project with big VE needs where the designers after much discussion were willing to sacrifice some internal real divided light mullions on the punched opening windows. That came back as an ADD to cost because now it took two glaziers to lift each lite into the frames.

Regarding welded versus knock-down frames, I tend to follow the facility standard of one of the healthcare organizations we do a lot of work for. They must "own" near to 100,000 installed frames so they have experience.

Welded Frames:
All exterior doors.
All interior doors greater than 36-inches wide.
All fire-rated frames.
Lead shielded frames.
Any opening identified as high use.

Knock-down Frames
Interior, non-rated doors less than 36-inches wide.
Steven Bruneel, AIA, CSI-CDT, LEED-AP
Senior Member
Username: redseca2

Post Number: 289
Registered: 12-2006


Posted on Wednesday, July 27, 2011 - 07:55 pm:   Edit PostDelete PostPrint Post

Ronald,

Mystery Solved!

I have been looking at an orphan post-it that has been floating around my desk for weeks. Written on it is "Ready-Set Curries". Curries is one of the numerous components of ASSA-ABLOY.
Lisa Goodwin Robbins, RA, CCS, LEED ap
Senior Member
Username: lgoodrob

Post Number: 139
Registered: 08-2004
Posted on Thursday, July 28, 2011 - 09:15 am:   Edit PostDelete PostPrint Post

Beth,

Thanks so much for sharing your research. You are exactly what makes this forum so useful! Please post more often.
-
Lynn Javoroski CSI CCS LEEDģ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 1284
Registered: 07-2002


Posted on Thursday, July 28, 2011 - 09:26 am:   Edit PostDelete PostPrint Post

Beth, thanks for sharing; Steven, thanks for the insight. This information gives us ammunition for future "discussions".
Andy (Unregistered Guest)
Unregistered guest
Posted on Thursday, July 28, 2011 - 11:41 am:   Edit PostDelete PostPrint Post

You can get a 3 hour rating in a knock down hollow metal frame if it is in a concrete or masonry wall.

I usually only see this application in replacing exisiting frames or cutting in new openings in existing concrete or masonry walls.

We use a lot of knock down frames in tennant office build outs when the contractors/owners don't have time to wait on welded frames.
anon (Unregistered Guest)
Unregistered guest
Posted on Thursday, July 28, 2011 - 12:38 pm:   Edit PostDelete PostPrint Post

Lynn,

What is the sanitation issue you mention? Is this a real issue, or just one of those things that seems like it should be so? There are an awful lot of cracks and crevices in a hospital that act the same as the joint in a knocked-down frame, but I have never heard a client camplain about any of those from a sanitation standpoint.

if you have something a little more scientific about the alleged sanitation issue with knocked-down frames, please share!
Lynn Javoroski CSI CCS LEEDģ AP SCIP Affiliate
Senior Member
Username: lynn_javoroski

Post Number: 1285
Registered: 07-2002


Posted on Thursday, July 28, 2011 - 12:59 pm:   Edit PostDelete PostPrint Post

Where it's really critical, we use FRP or stainless steel for chemical and biological resistance and other reasons (no metals in some labs). Otherwise, where we do use HM, it's just one less joint to seal, one less crevice to be concerned with. We use diatomaceous earth in frames in some applications, so there are numerous critters that we try to exclude. Without getting into specific types of facilities, I hope this answers your question, anon.
John Bunzick, CCS, CCCA, LEED AP
Senior Member
Username: bunzick

Post Number: 1334
Registered: 03-2002
Posted on Tuesday, August 23, 2011 - 03:53 pm:   Edit PostDelete PostPrint Post

Lead time on welded is longer, which is the only reason I ever had any push-back on using welded. Some jobs just are too rushed.

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