Gluing Treated Wood

This week’s question comes from Brian. He writes:

“Quick question on joining treated pine – I would like to face glue surfaced 2×6 treated pine boards. Does the fact that i am using treated lumber reduce the strength of the joint or make the glue less effective somehow? This is for an application that will have to be waterproof.”

My reply is actually an excerpt from an article I found a while back from Iowa State Univeristy. Full Article Here.
Deposits on the surface of treated wood present problems in gluing. Oil-type preservatives typically present more problems than waterborne treatments. Wood treated with very high retentions of creosote or pentachlorophenol in heavy solvents is essentially non-gluable. Low retentions of penta in light solvents may be somewhat more readily glued than wood treated with creosote. Wood treated with waterborne chemicals usually can be glued without major problems, if properly dried. Planing or sanding the surface before gluing is recommended to enhance bonding. Select the adhesive appropriate for the exposure condition among conventional wood adhesives. Only resorcinol resin glues provide completely waterproof gluelines with wood; urea resin glues and polyvinyl resin adhesives generate only modest water-resistant glue bonds. Some types of elastomeric construction adhesives offer good resistance to moisture and are much more tolerant of high wood moisture contents and low temperatures than conventional wood adhesives.

If anyone has anything to add, please do so in the comments section. I personally have very little experience gluing treated wood.

Category: Techniques

Comments

  1. Vic January 7, 2008

    It probably goes without saying, but wear a dust mask if you sand or are exposed to the dust of treated wood in any manner. I’m not sure of the newer treated woods, but all of the older methods used some pretty nasty stuff and better safe…

  2. Mark (http://) January 8, 2008

    No, you can’t glue it. However when you nail or screw into it be certain to use stainless steel. Regular steel will fail in a much shorter time, due to the chemical reaction with the preservative.

  3. tom hunt January 8, 2008

    I’ve had pretty good results using polyurethane glue on outdoor projects built from treated pine.

  4. Steve Quillian January 8, 2008

    Not being sure of what it is you are building, the strength necessary and all that, only that it has to be waterproof, there are other woods that can be glued. Cypress is a highly weatherable wood and while it’s not as strong as a treated pine, it will last just as long in many conditions and glues exceptionally well. I use it to make windows here in Tampa, Florida where moisture is a problem. Its an oily wood that grows in the swamps and doesn’t rot for years after it dies. Could you use an alternate wood?

  5. Keith January 8, 2008

    I’m based in the UK where we have pretty well banned the use of creosote so our treated timber is now tanalised which can be glued. The only 100% waterproof adhesive easily available in the UK is Polyproof, this is a resorcinol/ phenol/ formaldehyde; I’m not sure if this is available in the US but you should find something similar. The only downside of this is the dark red glue line.

    Avoid polyurethanes, long term they do not like to be cycled between wet and dry and in my experience the bond fails after a few years.

    Epoxy is another option, not as waterproof as resorcinol but sets clear. The wood needs to be completely dry though if you want a decent bond.

    Hope this helps

    Keith

  6. robert January 8, 2008

    I have face-glued treated 2 x 4’s to make 4 x 4’s and had no problems. I don’t know the type of treatment. The boards were standard treated lumber bought at Lowes and were slightly green in color.

  7. Tom January 8, 2008

    Source for the tech note on gluing treated lumber is Iowa State U. Extension Service.

    http://www.extension.iastate.e.....PM1033.pdf

  8. matt January 9, 2008

    I have never had to face glue PT lumber but when I finish a basement I rely on construction adhesive to do a majority of the holding on the pressure treated bottom plate. It may not be pretty but I am pretty sure it would hold up just fine.

  9. Robert (http://) January 9, 2008

    Personal experience with Gorilla Glue: it failed to perform; picnic table built with treated pine.

  10. REcorcinol made by dap is very expensive but very effective! I does leave a red line adter cured. THe glue joints are very brittle; meaning they do not take shock very well. But the joint is bullet proof under the atlantic ocean. LOL. Since the red line it leaves is very hard to mask, use masking tape to protect the part of the project you want to keep clean. Another issue is: thoroughly scraping, sanding, and planing the glueline after fully cured. REcorcinol takes about 2 days to fully cure, after that your gold.

    hope this helps

  11. I know that PL premium or PL 400 holds extremely well of pressure treated lumber. Fills gaps, drys rock hard, and is 100% waterproof!

    peace

  12. Greg Niederhaus September 8, 2009

    I would like to use the planks from a deck I built to lay an interior floor. My thought is to run the under sides through a planer, make lap joints to hide the gaps, and glue the planks to each other as I screw them in. Being that we typically leave a gap between planks for exterior use, can I get away with this idea if I leave an inch gap around the perimeter? It is for a restaurant and they don’t want food to build up in gaps. Dimensions are 12 by 12 feet. Any advice would be appreciated!

    •  
      thewoodwhisperer September 8, 2009

      Hey Greg. As long as you allow some room for expansion and contraction of each board, you should be fine. I don’t think you need a full inch around the perimeter. 3/4″ should be more than enough for that size room. And just keep in mind the time of year and the relative humidity. If its humid right now, you can install the floor nice and tight because the dry winter heat is on its way.

      Also make sure you let these boards acclimate. I would bring them inside for as long as you can before the installation. The outside humidity level will most likely be very different than the inside. So its important to get the wood acclimated properly before the install.

      Hope that helps.

  13. george nimo June 17, 2011

    will like to know the best glue to use to glue down treated wood to basement concrate floor .i am going to put a plywood on it as a sub floor for laying a hard wood floor .thanks.

  14. Sammy Little July 16, 2013

    I just bought some “F-26″ adhesive at Lowes and it says on the front: SUPER For Deck and Treated Lumber. It is cheaper than many of the gun adhesives, $4, and it is made by Leech.

  15. Tony Allen July 18, 2014

    I am custom building 26 porch columns. 8 foot tall in the past I made some with 10 2 x 4 s not treated for the tapered staves… now the customer wants treated wood …..it has to be strong and not come apart under pressure …what will be the very best Glue for this application

Leave a reply

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Online project based woodworking education.

3 Membership types

  • A la Carte
    Starting at $25/project
  • Subscription
    $129/year
  • Superfan Subscription
    $299/year
Learn more →

Simple Varnish Finish DVD

Coming Up


  • There are no upcoming events

  • There are no upcoming events

TWWGiveawayNov
bellforest200x200-tww10
EagleAmerica
Image Map
woodwhisperer-200x200-november
Advertisement