Hi Again

A while back I asked about the best caulk to use on exterior siding in Phoenix. The answers were great, if sometimes hard to find the products.

I am now in a position to begin work. I did a few test runs to see how the old caulk comes out and found a few things. The siding is a fiber board type (dark brown) and flakes or shreds when sc****d. It seems as if the original caulk was set not only in the seams but also between the overlaps of the boards.

I can get most of the material out from the seam, but obviously can't touch the overlap caulk. Will it be okay to caulk in the seams without doing so?

The second issue is that the original caulk was also laid in the indent part (1/2 inch +/-) where the boards join. This will be difficult to remove. Is it necessary to do so? Will the new caulk adhere if it isn't removed?

A third issue is the board material. The fiber shreds easily when the caulking is being removed. While I don't think it is a problem as it will be covered with the new caulk, I'm slightly concerns that because it shreds, the new caulk may not adhere well.

Sorry for the long post. Appreciate any help you offer.

John Pisacano
Phoenix, AZ