Hello:

I am about to apply the corner & window trim on my not-so-super-insulated house.

The siding is Fraser Evolution Bevel applied horizontally. The siding is mid-grey in colour and the trim is light-grey.

All butt joints between the siding and the trim must be caulked.

I would like to know the name of the best caulk with which to do this. The house is just north of Montreal, Quebec, Canada.

My concerns are:

1. Caulk failure, if there is such a thing.
2. Caulk dis-coloration, which I heard can happen.

Any advice on the proper caulk to use would be greatly appreciated.

Rob.

See here for some info.

Use the DAP Alex Plus with silicone, it's actually latex and I used hundreds if not thousands of tubes in my window business. Love the stuff. You can get it at Lowes in contractor packs of 12 tubes, at a reasonable price. Anyways the trick with caulking is to back caulk your joints. By that I mean put a bead of caulk on the trim and set the clap in it. Use an old damp towel to wipe off the excess and you'll have a clean joint that should last a long, long time since the caulk is under the cap protected from the elements. Dap may have grey, I've used tan before

So if a sealant has 12% movement and your caulk bead is 1/4", it is rated for 1/32" movement. If a sealant is 35% and the caulk bead is the same 1/4" it is rated for approx. 3/32".

Food for thought. OSI Quad and Tremco Dymonic are two good choices.

What blind carpenter would cut to a 1/4" gap between trim and siding. Siding is installed cut slightly over sized.

So you spring your siding into place then use a cheap sealant? Nice. I put on LP Smartside, 3/16" gap is required. I guess the lesson is look over your installation materials.

But smartwall, you're missing the point. The smaller the bead you use, the less movement the joint will take before failure, so couple that with a cheap sealant and the durability doesn't have a chance.

And if temperature or moisture changes cause a gap to sometimes go down to zero width, there is no sealant that will keep it sealed.

Thanks people!