Replies

1. 
   JimBaird | Jun 09, 2004 06:44pm | #1

   Vendors of enameled steel roofing, (very popular in SE US) sell a ribbon caulk that comes in a big flat roll.  It's for sealing seams of metal sheets.  It is 1/4" thick and 3/8" (approx.) wide, has a paper backing you peel off after laying it in place.

   It is very durable and very sticky.  Not sure how it would behave exposed, but applying it would be easy.

2. 
   Don | Jun 09, 2004 08:38pm | #2

   Too big for caulk alone - you should put a bead below it in the gap, ao the caiulk doesn't have to stick to 3 sides at once & fail. Go to several editions of FHB back & look for an article on this. Home De-Pot has the stuff. Caulk doesn't stick to it, so it only has to stretch one direction.

   Don

   The GlassMasterworks - If it scratches, I etch it!
1. 
   GoldenWreckedAngle | Jun 09, 2004 08:41pm | #4

   You posted while I was typing - I like your idea better than the foam tape. Good suggestion.Kevin Halliburton

   "Do you see a man skilled in his work? He will serve before kings; he will not serve before obscure men." - Solomon

2. 
   BillHartmann | Jun 09, 2004 08:44pm | #5

   A copy of the article is on the FHB main web page.

3. 
   GoldenWreckedAngle | Jun 09, 2004 08:39pm | #3

   I would use a 2-or-more-part, polyurethane-based, elastomeric sealant. Check the label and find one that complies with either ASTM C 920 Type M Class 25, or FS TT-S-00227E Class A. I think PL has a 2 part door and window sealant that meets those requirements.

   Those are the specifications we use for expansion joints with disimilar materials that might see a bit of movement. I'm not sure if you have the depth for a backer rod but on a joint that wide you will get the best results if the sealant only adhered at the edges and not the middle. You might be able to back it up with a small strip of foam tape instead.

   Kevin Halliburton

   "Do you see a man skilled in his work? He will serve before kings; he will not serve before obscure men." - Solomon

1. 
   OneofmanyBobs | Jun 09, 2004 11:26pm | #6

   There isn't enough depth for a backer rod but I can probably find some slick tape to go on the bottom.  I was fairly sure it wouldn't work good if just filled with caulk.  I'll give it shot.  The sill has to go over a flange on the door frame and its either wide caulk or rabbet the sill very thin.  Either way not great.

1. 
   FastEddie1 | Jun 09, 2004 11:32pm | #7

   You might get by with a layer of blue masking tape for the backer rod.  Maybe two layers.  The caulk will probably be stronger than the paper tape, so the tape should tear apart if there is movement, once the caulk is cured.

   What about using a 1/4 inch wide solid filler material down the middle of the gap, so you end up with two caulk beads each about 1/8 inch wide?  Maybe a rip off a scrap of solid surface material.

   Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

1. 
   JohnSprung | Jun 10, 2004 03:02am | #11

   > so you end up with two caulk beads each about 1/8 inch wide? 

   Wide is actually good for caulking.  The material can tolerate a movement of some percentage of the width of the gap.  If it's good for, say, 25%, the half inch gap can move +/- 1/8".  But on a 1/8" gap, it'll only be good for 1/32".

   Round backer rod gives you a large surface to bond to on the sides, and thins out the middle.  That's a good thing, because it puts most of the movement in the middle and protects the bonds.  Ideally you want the middle to be about half as thick as the gap is wide.

   -- J.S.

1. 
   FastEddie1 | Jun 10, 2004 04:22am | #12

   I agree with all that.  However, in this case, the total joint width is less than 1/2 inch and the depth is about a quarter inch, so it's not normal.  If it was as deep as wide, then the backer rod would be a good idea.  I'm afraid that any backer rod in the 1/4 inch ddep groove will make the caulk very thin.

   Actually, now that I've had supper and a nap, I would put the tape on the bottom to act as a bond breaker, and fill it solid.  That's only a 1/2" x 1/4" joint.

   Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

4. 
   dieselpig | Jun 09, 2004 11:49pm | #8

   Why not use 1/2" backer rod and split it down the middle with a razor knife? 

   Too easy to work?

1. 
   OneofmanyBobs | Jun 10, 2004 12:04am | #10

   This joint will get walked on sometimes.  I wasn't sure that backer rod will take that kind of abuse.  Thought mabe a really tough elastomer would be better.  Anyway, a lot of good things I hadn't thought about.  I'll see what kind of caulk I can find and give it a try.

5. 
   mdresimprov | Jun 09, 2004 11:50pm | #9

   Sika Flex A1 or Sonneborn sealants will work well.

   MES

6. 
   reinvent | Jun 10, 2004 05:35am | #13

   3M's 5200, used in boat building. HD carrys it.

7. 
   GoldenWreckedAngle | Jun 10, 2004 07:40am | #14

   Bob,

   You know, I hate to suggest that we'll beat an idea into the ground around here but it's been known to happen. The idea is really pretty simple. 2 (or more) part polyurethane - stick it at the edges and don't stick it in the middle. You've got two or three good suggestions on how to do that, but in my experience it's hard to screw 2 part poly's up, even if you skip all of of our brilliant suggestions and just stick it on straight.

   That's why we spec it on the screwy stuff- we like to leave the intellectually elite minds that are usually charged with applying it to contemplate more significant concepts. <G> 

   Pick one, take care of it, and redo it in ten years if necessary. Good luck!

   Kevin Halliburton

   "Do you see a man skilled in his work? He will serve before kings; he will not serve before obscure men." - Solomon

1. 
   OneofmanyBobs | Jun 10, 2004 10:26am | #15

   Well, I asked because its a bit unusual.  I'll try the 2-part stuff.  My usual is a single-part poly, but its not really tough enough.  Would be nice if this lasts 5 years.  My usual stuff  has a 50 year guarantee.  Wonder if anybody saves the receipt long enough to ever make a claim.

1. 
   GoldenWreckedAngle | Jun 10, 2004 10:36am | #16

   I can just about guarentee you the 2 part will outlast your receipt by several years. By the way, you asked a great question and I didn't intend to trivialize it. Hope you didn't take it that way.Kevin Halliburton

   "The Greek comic poets, also, divided their plays into parts by introducing a choral song, ... they relived the actor's speeches by such intermissions." Vitruvious, (Book V)

1. 
   OneofmanyBobs | Jun 10, 2004 11:02am | #17

   Some stuff that seems simple isn't and vice versa.  This is one of those little things that can cause big problems if not done right.  There's a deck adjoining the door.  Let water get in under the sill and damage the framing behind the ledger, not good.  There's plenty of flashing but this needs to be as good a job as I can reasonably do.  Got a lot of good suggestions.  This is a replacement door and I'd not have done it this way if I had a choice, but this is the only way it would fit and it was not an easy job.  Brick veneer and rough-sawn full dimension studs.  Do not want to come back and fix it.  If the 2-part stuff works well, I'll use a lot more of it.  I'm tired of the guaranteed non-shrinking stuff that always shrinks.