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Drainage on framed trellis?

Installed a pine privacy trellis on boundary wall. Will try attach some pictures. 

Trellis and posts were pressure treated, treated with fungicide, treated with Ronseal preserver and finished with Textrol oil. 

My issue is I am now concerned that water will pool in the bottom of the trellis frame, which will eventually cause it to rot. Should I drill some holes in the frame so the water can escape?

Appreciate any opinions or recommendations on this. 


  • amancalledgeorgeamancalledgeorge South LondonPosts: 2,307
    My thinking would be that if you made holes in the treated wood you would expose more of the interior to the water. So can't really see much benefit in doing that. It will rot eventually like everything else but can't imagine it would be any time soon. 
    To Plant a Garden is to Believe in Tomorrow
  • Ok, I can see your point. Climbing plants will eventually grow around the trellis, so I won’t be treating again and put as much effort into protecting before installing. So hopefully will last a good while. Any other opinions on this?
  • FairygirlFairygirl west central ScotlandPosts: 48,907
    Pine isn't going to last unless treated regularly. It isn't very suitable for outdoors in the UK, especially in a wet area. Most trellis is made from suitably treated, more appropriate timber, because of that.
    I'd agree with @amancalledgeorge - drilling holes will just mean more work protecting it.
    It's a place where beautiful isn't enough of a word....

  • rachelQrtJHBjbrachelQrtJHBjb South BucksPosts: 814
    I have similar trellis from Jacksons Fencing. It's about ten years old and is framed so water gathers in the bottom. So far, so good, with no rotting. But their products do come with a 25 year guarantee. Not sure if this feedback helps.
  • Trellis came from B&Q and was the best I could find without tripling the cost. The fact that is pressure treated and all the effort (and cost) I put into treating myself, I hope this will give the trellis as much longevity as possible. Won’t be replacing with a hardwood at this stage. 

    Checked out the Jackson’s website and seems like the trellis they offer with a 25 year guarantee is also a softwood. Feedback that similar framed trellis has lasted for 10 years definitely helps. This aligns with other comments that are against drilling holes in the frame to allow water to escape. 
  • FairygirlFairygirl west central ScotlandPosts: 48,907
    A better way of making trellis last is to make it yourself with roofing battens. Much cheaper and sturdier.
    If it's going to have climbers over it, it doesn't need to be fancy either. Simple screens done horizontally are even easier, and very 'in' at the moment too.  :)

    If yours has been well treated and painted etc, you should get ten years out of it though. Good stuff will last much longer.
    It's a place where beautiful isn't enough of a word....

  • Ferdinand2000Ferdinand2000 Posts: 537
    edited October 2020
    Personally I'd drill 2-4 small drainage holes per panel in the dry, and if I was feeling enthusiastic do the inside of the holes with a quick in-out with a brush filled with preservative (whichever not-creosote you prefer).

    My concern would be the narrowness of the members relative to the size of the holes, so I might do the holes (say 10mm) on the side level with the bottom of the groove, with an up angle towards the groove as you do when eg running a cable into a house for an external light.

    Making your own with roofing laths is a good call (come typically in 1 x 2 inches pre-treated) - that is usually about 50p/meter, treated. I only have one small run of trellis, which came as a couple of expanding panels (like scissors - not sure what they are called) with no frame so I made my own frame.

    I have something I need to block similarly, and I'm not sure how to do it - even wondered about higher level pleached trees above my hedge / fence.  But need to be sure I will be here long enough to be worthwhile.

    “Rivers know this ... we will get there in the end.”
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