Replies

1. 
   Guest_ | Nov 17, 1999 02:34am | #1

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   Hello Felipe,

   I can tell you how I handle these joints, but things may be different for your area, depending on climate and temperature changes.

   I live in a hot, humid region, and expansion is the biggest problem we deal with. For that, we leave approximately 1/8" gap (or less depending on siding material). This exposed gap can be treated in many ways. Some are not viable on natural colored wood siding, but there are other options.

   1. The use of "H" channels, made specifically for the siding is a common, although in my opinion ugly, solution. These channels slip on the end of one piece of siding, and the end of the next piece slips in the other side.

   2. Caulking the seam. This works ok, but the caulking must be stained, or painted in order to match the siding color. It must be recaulked every few years. If the caulking cracks open, you will have an open seam that will allow water penetration. On natural colored wood siding, this will show, even if you use clear.

   3. Backer strips. These have been used for over a century. You can use flashing material, tar paper (#30), or you can buy these strips. I personally prefer the tar paper strips. They are easy to use, and easy to cut. You simply cut a piece that is a little longer than the width of the siding, and wide enough to overlap the siding seam by about 2" - 3" on each side. When you install a piece of siding, slip the backer behind the end, with about 2" - 3" sticking out. Make sure the backer does not go BELOW the siding panel you are working on. Each successive row of siding will cover the top of the backer, and keep it hidden from view. Then you just go on installing the siding. There is no need to seal the seams with anything. Again, this method will depend greatly on type of siding used.

   Every type of siding that I have ever used has a manufacturers suggested installation procedure. Be sure to read it FIRST. They may very well have a different method, or a product that they suggest. Also be sure to BACK PRIME/SEAL the siding. This includes the ends as well. I coat the ends at least twice before installation.

   I am sure that there are many here who could give a different installation procedure based on their climate and temperatures, or even their preference. This way you can get several methods, and choose the one best suited for you and your particular type of siding.

   Just a thought...

   James DuHamel

1. 
   Guest_ | Nov 17, 1999 03:48am | #2

   *We cut all our wood trim and wood lap siding with a 45 bevel We prime all cuts, and make all our joints over framing even if we have sheathing. We try to set all cuts so the Hollywood side is the most prominent (so you are looking over the joint instead of into it).If you are cutting bevel siding , like 1/2 x 6 clapboard, you will find that the cut not only runs at 45 deg. but since it also follows the bevel , it is NOT a plumb cut. This makes it more attractive, and further helps to take up some of the expansion and contraction. Some wood moves more than others, most of our lap siding is red or white cedar, relaitively stable thru its length. Another big help in controling movement is to backprime, and edge prime all exterior wood, and only work with seasoned stock. This is another control on the expansion / contraction due to change in moisture content.If we're working with Cement siding we just butt joint, and put a spline BEHIND the joint. Then go back and caulk the joint before painting.

2. 
   Felipe_Lana | Nov 18, 1999 12:36am | #3

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   Hello James:
   Thank you for your recommendations. Unfortunately in my case the siding is up and running for three years to the date. I used local pine timber 1x2 x 6" in strips that are up to 9 feet long. I treated the wood with oils and a product to protect it against a worm that eats pine. I had it milled as tongue and groove. Being that the wood is up I want to find a way to caulk or fix, which ever might be the best term, the existing gaps. I tried plastic putty thinking that it would have more elasticity but it fails in time. Based on this xplanation what do you recommend?
   By the way, I live in Mar del Plata, Argentina, and live in the only all stick frame house in the city. The climate here is very humid with temps ranging from 0 to 42 degrees celcius.
   Again, thanks for your reply!!!!
   Warm regards, FL

3. 
   Guest_ | Nov 22, 1999 02:12pm | #4

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   Hello Felipe,

   I talked to several other siding installers in my area about your situation. We all came to the same consensus that your best bet is to go ahead and caulk the seams. Use a clear 100% silicone sealant, and smooth it with your finger. Wipe off any that gets on the face of the siding. This should last for several years before anything else would have to be done.

   James DuHamel

1. 
   Guest_ | Nov 23, 1999 03:29am | #5

   *I put a 3" or so wide strip of alum flashing behind joints and under corner boards, trim, etc., overlaping lower course.

4. 
   Felipe_Lana | Jan 04, 2000 11:40pm | #6

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   How do you deal with contraction and expansion of siding joints