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How to seal garden shed gaps?

I have this garden shed done by previous owners. As you can see, there are gaps where the panels meets the base and water gets through the gap inside shed. What would be the effective way to seal these gaps? Probably, I will have to fix it all 4 sides 🙁
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EricL

Hello @bh039

I suggest having a quick look at this guide - How to waterproof a shed floor. I also propose cleaning the "U" channel where the panels are sitting in. The purpose of that channel is to catch the rain hitting the wall and diverting it to the ends where it will flow away. If that channel is full of debris water will not flow properly and you'll get small puddles developing in the channel.

Here are other discussions regarding sealing your shed:

How to seal the bottom of shed walls? by @jjebw
How to seal the bottom of the shed? by @MattR85
How to waterproof existing garden shed? by @basilmabraham
How to water-seal edges of an Absco garden shed? by @bennyboy

If you have any other questions we can help with, please let us know.

Eric

bh039

Hi @EricL - Thanks for your response. I dont have any opening at the end of U channel. So, will have to stop the rainwater getting into it.

I checked the links you shared. Most of the it prefers to use silicone to seal the gap (either inside or outside). I would need a lot of it if I chose to do it from outside - have to fill up the U channel. I can't use angle to stop water entering the channel due to its being zig zag walls.

Someone preferred to use Polyurethane. Do you think it is worth a try?
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Nailbag

Hi @bh039

Just use roof and gutter clear silicone. It's cheap and effective. It's what I used and it works a treat. I also lifted the shed walls with a pryer enough to apply some underneath. Then on the next day used the garden hose on it to check for areas I need to top up with more silicone.

Nailbag

JacobZ

Hi @bh039,

As @Nailbag has mentioned, roof and gutter silicone would work fine and is cost-effective.

There's no need to fill the whole channel, just apply a bead to seal the bottom edge of the sheets.

You can then use the hose test to look for areas that need to be topped up.

Let me know what you think.

Jacob

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