Water coming through shed walls.

Discussion in 'Landscaping and Outdoors' started by Gav8452, Jan 24, 2022.

  1. Gav8452

    Gav8452 New Member

    Looking for some advice. Purchased a tongue and groove (T&G) shed (10 x 8) from an outfit called gardenstreet. The shed arrived mid year 2021. I placed the shed on 35 breeze blocks that were set and leveled using mortar on top of tarmac (assembled using moulds). Took a week to construct the base ensuring the blocks were straight, level and solid. The shed floor was used to position the blocks, ie specifically built for this shed.
    IMG_20220107_151555.jpg IMG_20220107_151629.jpg

    The shed was painted three times using Sadoin Superdeck (expensive stuff). All was good until we got some heavy rain and I noticed this

    This is the worst area affected, there are other areas on other walls. We contacted gardenstreet (shed built by Mercia) and they suggested painting the inside of the shed. We rejected that and then they claimed there was not enough ventilation around the shed. That was put to rest as well. Now they are trying to wash their hands of any responsibility because of the base and the tarmac...ie it's not one of our "recommended" base types.

    So I am trying to get to the bottom of exactly why this is happening and I've sought advice. I wanted to post this here to further confirm what we have concluded is the cause and without giving too much away here are some photographs showing things we have found





    Photo from outside after a further coat of paint (Total of 4)
    So obviously we have sealed all the holes pictured...and more but yet it has made no difference to the water ingress. Any thoughs or comments would be appreciated.


    Attached Files:

    Last edited: Jan 24, 2022
  2. Astramax

    Astramax Super Member

    Can you post some further pictures of the roof please.
  3. Gav8452

    Gav8452 New Member

    IMG_20220124_153757.jpg IMG_20220124_154637.jpg IMG_20220124_154704.jpg IMG_20220124_154725.jpg IMG_20220124_154757.jpg IMG_20220124_154807.jpg IMG_20220124_155051.jpg
  4. Truckcab79

    Truckcab79 Screwfix Select

    With respect It’s a cheap shed, (that doesn’t mean it was actually cheap!) and they’re not designed to be a fully waterproof structure.
    Yours is particularly bad.

    Shiplap is a better option than T&G as you have more overhang on each board to help shed water. On yours the water is tracking back in around the joints and coming inside.

    Difficulty is that sheds are a bit hit and miss. Anything that can stop water coming in is better done during construction. Joints could be glued, a membrane installed over the frame and under the boards etc etc. nobody does this on an off the peg shed but would be normal for a custom build, home office, garden room, workshop etc…..at about 10 times more than you paid.

    If it hasn’t got guttering you could add some. Anything that keeps water from the sides. You could laboriously caulk or seal each board joint and then repaint. You could paint the inside as they suggest but that just means water gets trapped in the joints and rots the boards out.

    I’d you’re on here hoping to get something to show them to prove that experts say that their product is rubbish then I doubt they will care less as you’re essentially getting the arguably uninformed opinion of some bloke off the internet.

    Sheds are generally rubbish.
  5. Truckcab79

    Truckcab79 Screwfix Select

    Roof felt looks nicely applied though. :D A few more nails wouldn’t have hurt but that’s not the cause of your water ingress.

    Photograph the side. Bet the overhang barely clears the sides.
  6. Truckcab79

    Truckcab79 Screwfix Select

    Worth popping the corners off too. They’re generally just laid in. No joint as such behind them. Could be running in there and tracking along. Dependent upon size of gap you find, a healthy dose of expanding foam or your sealant of choice.
  7. Gav8452

    Gav8452 New Member

  8. Astramax

    Astramax Super Member

    Did you use a felt adhesive on the overlaps, the felt nails are to few and far between, and yes fit gutters.
  9. Truckcab79

    Truckcab79 Screwfix Select

    That last picture is I suspect a large part of the issue. Overhang is minimal and felt is point back toward walls. Couldn’t be much worse though very common.

    Mini-guttering and run it into a water butt. If you can, peel back the felt at the edges and insert an angled strip of timber so that the felt is vertical too or at the very least make sure it’s running into the gutter or turn it under / cut it back so it cannot run back toward walls.
    I-Man likes this.
  10. Gav8452

    Gav8452 New Member

    Thanks for the reply. Yeah it's been pointed out to us that it is a cheap shed, but not a cheap price (£1500). What makes this 100 x worse is that it was a gift to my partner from her mother that passed away late last year. I've had a few sheds before and still have one thats the best part of 30 years old and even that isn't letting in water like this...I've never seen something this bad, particullarly since the inside is now so damp, mould is growing.

    I have taken some extra steps to try and resolve the issue of the water tracking round the board. I've painted it a few more times, paying particular attention to the joins in an effort to create a seal which I've had some success with but don't think it's a permenant solution, what with wood expanding and contracting. If I undestand you correctly I've also sealed the corners with silicone which can be seen if you look closely at the external pictures.
  11. Astramax

    Astramax Super Member

    It's a very nice gift and I'm sure it will be even nicer when a few problems are addressed. It isn't a cheap shed it's an inexpensive one. :)
  12. Astramax

    Astramax Super Member

    Between the roof felt and the timber trims on the gable ends fill the gap with a waterproof sealer such as a clear gutter sealant as it will outlast silicone.
  13. Truckcab79

    Truckcab79 Screwfix Select

    Always amazes me how much sheds cost. Too late now but I’ve always found the best options are suppliers on eBay who make to measure. My 20x10 workshop in 22mm shiplap was made to measure with double doors, extra height roof and 4 glazed opening windows including assembly and delivery from Birmingham to Herts for £1800 (4 years ago admittedly). That’s where I always direct clients to though often I’ll do the build as it’s easier for me to waterprooof, insulate, run power, board out etc if I’m doing it before assembly.

    As far as the corners go that will certainly help. I’d be inclined to take them off if they continue to leak and bed them back onto the sealant. It will be more effective than just filling the gaps at the edge.

    Guttering is your best option first though I suspect.
  14. MRY

    MRY Screwfix Select

    Well, that's a nice shed, the floor arrangement looks good. Those very small holes here and there should not be letting in so much water through the shiplap.

    Put gutters on straight away, though. Make sure that where the drip line (felt) is in the middle of the gutter. Get 4 1/2^ (112mm) gutter and brackets, reduce joints as much as possible, you can get 4m lengths if 3m won't do, use a stop end an one end of each gutter and an outlet stop end at the other if that's the way you want to do it. You won't need a massive fall on the gutter. Make sure the edge of the felt is in roughly in line with the top edges of the gutter, don't have a big gap. Get 68mm pipe. Try to attach brackets and clips to something decent, if you have to screw into boards and not battens, put some extra piece of board on the inside to spread the load and get a decent fixing. Use enough brackets and clips, I think Screwfix sell both in packets of 10 so you will have some spare pipe clips.

    The roof's felt could do with some extra fixing. Get some lap adhesive, carefully remove any clout nails alread in, apply adhesive and fix with again clouts (I prefer torch-on, but you've already got the felt on it).

    But it does look a nice shed.

    Whatever else you do, don't paint the inside, the timber will have the wet sealed in, it will flake off or the boards rot, or both.
    Last edited: Jan 24, 2022
  15. Gav8452

    Gav8452 New Member

    Hi Astramax, thanks for the reply. No adhesive was used...it didn't come with any. If I recall I counted out the roof nails that were provided and that was my lot. I had thought about your suggestion of sealing between the felt and the timber trims as its on the gable end where the water ingress is at its worst from what I believe is water running down between the felt and timber trim.
    Astramax likes this.
  16. Astramax

    Astramax Super Member

    For the small cost involved I would seal the end to see if that puts an end to the water ingress cause, this will if successful see you into the spring and better weather when a more permanent repair can be tackled.
  17. MRY

    MRY Screwfix Select

    The felt should fold over the edges of the roof at the gable ends, and the trims should sandwich the felt between them and the batten the felt is folded over. It sould not matter if in effect there are no trims at all, the felt should still keep the water out. Any water running between the trim and the felt should drip off either the trim, or the batten, or the felt if it extends far enough, which it should.
  18. Gav8452

    Gav8452 New Member

    Thanks MRY for the info and suggestion. Looks like gutters are the consensus as well as securing and gluing the roof felt so I'll give all that a try. I had also considered adding additional strips of wood to the gable ends on the roof as opposed to sealing between the felt and board. I've seen this on a few older sheds and I'm assuming it would help divert water overflow from the gable ends into the gutters.

    Last edited: Jan 24, 2022
  19. Gav8452

    Gav8452 New Member

    Yes this was how I fitted the felt. The gable ends sit under the four panels that make up the roof allowing the felt to directly fold over the gable end and then be held in place by the wooden trims.
  20. MRY

    MRY Screwfix Select

    Hang on, is that what you've actually got? I'd looked at the first pictures, showing a piece of timber trim hailed to the gable end.

    So what's that, and how's it fitted? What happens to the felt under it?

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