3 posts / 0 new
Last post
treesb
Deck

We installed a new deck and used untreated wood and painted it. Since the hot weather has come, sap is coming out of some of the boards, sticky! sticky! Is this natural?:confused: We have power-washed it and sanded it and want to paint it again; but don't know if something else should be done first. Can anyone tell me how to get rid of the sap and keep it from returning?
Treesb

canuk
Re: Deck

The "sap" oozing from your deck boards is a natural product of the wood...... actually called pitch.

Your deck wood is probably made of a member of the conifer species ...... likely pine ..... which have large pitch pockets.
When the wood gets hot enough it melts and runs out of the lumber .

Properly kiln dried lumber that has been heated to more than 160 degrees solidifies the pitch usually does not suffer from this problem. Likely the lumber used on your deck was either not kiln dried or wasn't dried at a high enough temperature to cause this solidification.

There's not a lot you can do about the problem at this point except live with it. As the deck heats up in the summer pitch will continue to run from the boards.

There is no sealer made that can contain it under these conditions.

But the news is not all bad ........ a bit of turpentine on a rag will remove it quickly and eventually the pitch pockets will run dry.

Hope this helps. :)

deschenes3
Re: Deck

I have the same problem except I used pressure treated wood 13 years ago. I painted mine and now there is sap coming through several older boards?

TV Listings

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