Home>Discussions>PAINTING & FINISHING>exterior caulk separating from wood
3 posts / 0 new
Last post
exterior caulk separating from wood

Hi, I have a 1920s wooden bungalow that I recently had repainted about 7 months ago. Around March, I started noticing that the exterior caulk had started to separate from the wood inbetween the wooden boards. I have a couple of questions.

1. Should the space between the wooden boards have been caulked on the body of the house? I live in a humid climate. Would that have influenced the decision to do this?

2. For future reference (since I have to get this fixed), what type of exterior caulk do you recommend and where should they be putting it?

Thanks for your help and advice!

Re: exterior caulk separating from wood

Jellybean -

What has been caulked, the verticle seams between butted clapboards or do you mean someone caulked the underside of the clapboards. The underside in not normally caulked. All verticle joints should be caulked. You must anticipate how water will drain from the siding and prevent it from getting behind the siding. For exterior use I prefer a urethane caulk such as Vulkem. Elastomeric latex caulks are also good.

Re: exterior caulk separating from wood


A couple of things. First, did you prime the areas first? If not, this could be the cause of the separation. You should first prime, with a really good exterior prime, such as an alkyd, before caulking.

I have used a latex caulking compount, after priming. I make sure that the caulking compound is pressed into the joints by using either my thumb (messy) or a damp sponge to get a smooth finish. Then after the caulking has cured, about a day or so, I applied the finish coat(s)... I use two.



Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.