Fish shed problems :-(

[PeterUK]

I have been steadily doing up the shed over the last few months, fitting a few hours here and there after work (usually I'm down the shed around 2am to 4am). As it snowed heavily on Monday here I didnt go to work and managed to do quite a lot and only had to lay and glue the lino before I start building the racking.

I noticed there were a few dark patches that have appeared over the last few days on the back wall. I have just removed the 6 coats of paint with a 1600w heat gun and when I stripped out the mastic along the wall/ceiling edge there was a small but steady trickle of water.

There are now two oil filled radiators (3KW and 2KW) turned on to the maximum to try and dry any damp wood before repainting and sealing.

The leaking wall is the back wall and I will have to completely remove the 18ft of back fencing before I can get anywhere near treating and or repairing it.
I do NOT care about what it looks like once treated as this is something that can only be done once and I dont want to remove the complete back fence every year or two to re-treat it.

Is there a product that can TOTALLY waterprood/seal a tongue and groove wooden shed wall ?

I am thinking of using one of these products and treating the entire outside of the shed (walls and roof, even though the roofing felt is only a few months old and has 3 layers) apart from the front as it faces the house (and the old dragon will start moaning )

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[MatsP]

If it's the ouside wall that is leaking, then you could delay fixing it to a more suitable time by putting a water-proofing on the inside to prevent the wet from getting further in. Then you can take down the fence and replace the outside boards when weather is better or when it's more desperate. The drawback is that you may have to replace the structural timber as well.

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Mats

[OldMan]

If you have mounted the tongue and groove with the tongue up, it should shed water very well on its own. If you have mounted it with the groove side up, there is nothing that can be done short of a complete new covering to seal it because the groove will trap any slightest leak of moisture that migrates through any membrane covering. An intact and correctly installed tongue and groove can be effectively sealed to prevent moisture build up in the wood itself with nothing more than a good paint since its shape will shed almost all water with no coatings.

[PeterUK]

The shed has been used for the last 7 years to house reptiles with no problems. I'm guessing that the wood has aged and deteriorated to some degree in a small area and so is letting in water, I have visually checked and cannot find any obvious holes/splits.

[MatsP]

Yes, finding leaks can be a bit hard sometimes, as water can run along things - so where you actually see the water may not be where it came in, if you see what I mean.

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Mats

[L number Banana]

Kind of a girly solution but it works for this girl: use some beet juice to track the leak. Leaves a nice pink trail.
You can safely use rubber basement seal inside if you need to, no VOCs to hurt the fish.
Good luck.

[PeterUK]

VOC's ! ! !

[L number Banana]

oops sorry, may go by a different name there - VOC's Volatile Organic Compounds - stinky nasty stuff in many paints and things.
here's the wiki link http://en.wikipedia.org/wiki/Volatile_organic_compounds
Pure latex rubber like that used in mask making for theatres are natural and will form a true rubber barrier. You can find it at many craft stores. Some people have used it to coat tank backgrounds but I haven't tested it myself. Stinky but apparently naturally stinky:)

[sidguppy]

avoid the VOC's by all means as much as possible

this stuff -terpentine for example, or thinner- is highly toxic to all aquatic life, wich ofcourse includes fish

I can't tell you how many times I've spoken people that had a problem like "all my fish died, but the filter's fine, changed water yesterday, no diseases...."

"maybe you've been painting doors in the same room?"

"oh shit"

[Birger]

I noticed there were a few dark patches that have appeared over the last few days on the back wall.

If your shed is like most it probably does not have much for overhangs around the eaves, and what happens especially with snow (unfortunately I have to deal with snow quite a bit)is you get seepage back in under the edge of the eaves.This happens a lot here if proper precautions are not taken for a buildup of ice and snow around the edges of a roof but can seep back even with rain. What will help this (if this is the problem) is a piece of flashing tucked under the last row of shingles and left out over the edge which will not let the water seep back towards the building.

A picture of the edge of the back wall where roof meets wall would show me if this would help or not.

No matter how much you seal it or what product, with weather and age even the best applied sealer will crack or the moisture will affect the wood and allow moisture through somewhere eventually, the best is to keep most of the water right away from the wall.

I hope I explained myself clearly.

Birger

[L number Banana]

Good call, Birger I forgot about the unusual snowfall.
Here's an illustration of an ice dam:

[PeterUK]

That looks like the problem

I have now coated the roof and entire back wall with liquid rubber ...... twice.
After the snow melted there was torrential rain for a few days and not a drop appeared on the inside, so it looks like that its all good now
All walls repainted, electrics reconnected, flooring down, rebuilding the back fence tomorrow and starting on the racking at the weekend ..... oh yeah