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wooden shed walls leak

Help Second hand shed looked dry but now it is up in the garden the walls are all leaking! It is horizontal tongue and groove no sign of rot. Anyone any good ideas of how to leak proof it??


  • DovefromaboveDovefromabove Central Norfolk UKPosts: 80,390

    Hi Jackie image

    Is it the walls letting in the water or the roof absorbing the wet and it running down the walls?  

    The roof may need new felt - that's a pretty straightforward job 

    If you're sure that the rain is coming through the walls, check that they're the right way up - with tongue and groove, the tongue should be at the top. 

    Has the wood been treated in any way?

    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh

  • Hi, Jackie......I've had this problem in the past and to be honest most sheds with ship-lap or tongue & grooved boards have a little seepage during very heavy rain. However, you could seal the gaps (during a dry spell) with either clear silicone sealant or weatherproof caulking......both applied with a mastic gun.

    Good luck.

  • DovefromaboveDovefromabove Central Norfolk UKPosts: 80,390

    Just another thought - was the shed under cover when you bought it?  If it had been stored in the dry the wood might have shrunk and loosened the joints.  If that's the case a good soaking in a few downpours should swell the joints and cure the problem image

    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh

  • Perhaps it would be apt to add this to this thread.

    The cheap mineral felt sold & used for shed roofs has a very limited usually succumbs to high winds or rotting after a very short while.

    I have a large/ish shed and summerhouse, both were felted as above when new. When they needed re-felting, I decided to have them both 'hot felted' by professional cost £100 per building and came with a 25 year guarantee.

    The process involves the roof being stripped clean, an under-felt being applied, this is heated & melted with a flame-gun, next a heavy duty mineral felt is laid on to this and both are fused together, again with the flame-gun.

    No nails are used and it's a really neat job.   

  • jackie d2jackie d2 Posts: 2
    Thank you for replies. We put new felt on the shed and yes the walls are the right way up! The rain came before we had time to paint it - but that is the next job on the list once the rain stops and it has dried out. The shed was in a sheltered position, so it probably does need to weather again to swell the joints - well it is certainly getting its fair share of rain image
  • DovefromaboveDovefromabove Central Norfolk UKPosts: 80,390

    Hope it resolves itself without too much dampness.   If it continues it's possible to put an outer cladding of weatherboard on the walls - you could even introduce some insulation when doing it - just think how cosy that'd be image

    Good luck!

    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh

  • My friend, who is recently widowed, has a problem with her shed leaking on one side. The shed is in a corner, and the leaking side is against a high wall. There is a gap but not wide enough to squeeze in and nail shiplap, you could paint with a long handled roller. She is worried because she keeps her freezer in the shed, so obviously there are electrics involved. We were wondering if there is something she can paint it with to keep the water out when it rains heavily? Many thanks, Alison
  • FairygirlFairygirl west central ScotlandPosts: 47,279
    I'd put something on the inside of the walls  - preferably a decent layer of ply [or similar]  that could be treated first with a stain or paint.  :)
    I'd also find out if the freezer is suitable for being outdoors. You can't just put a standard freezer into an outbuilding of that sort. 
    It's a place where beautiful isn't enough of a word....

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