How to seal the shed?

[adnanqureshi]

Hello,

I recently acquired a new shed, but it had gaps from the floor area to the roof. To address this, I filled the floor gaps with cement to keep water, dust, insects, and air out of the shed. However, during the last few rainy days, water has been seeping in from all sides of the shed, with no apparent source in the middle or any other specific area. Could you please advise me on what steps I should take now? I am really surprised how this water came in.

Thank you

[adnanqureshi]

Thank you so much.

Appreciate your help. I will give a go and will let you know if i need further assistance.

Kind Regards,

Adnan

[adnanqureshi]

Hello,

Hello,

I desperately need help with this shed.I have now connected its downpipes to the stormwater tank which has improved the water on a couple of sides of the shed but still the water is coming in.To seal the gaps of corrugated walls on the floor,we have put cement and i think it has gone deep and thats why may be the water is coming in.Can someone please advise what should we do.Please note one side of the shed is exactly on the concrete slab and the rest is below/under it.

Thank you

[JacobZ]

Hi @adnanqureshi,

Thanks for the follow up question. 

I have moved it to your post from earlier so all the information is in one place.

Have you followed any of the advice I offered earlier? 

My suggestions would remain the same.

Let me know if there's any issues or if you have any questions about this advice as it will still be the best way to address the water ingress issues with your shed.

Jacob

[adnanqureshi]

Hello Jacob,

Should i remove the cement which we have put to fill the the gaps on the floor.I am hesitating to do so because i think i might either damage the shed itself or the concrete foundation which costed a lot.

Should i try to remove the cement from outside shed which is in direct contact may be to the ground and taking the water in?

In addition, please guide how should i seal this side which is exactly on the concrete.Sorry i messed up all the information which you had offered earlier.Kindly explain again so it can make some sense to me.Appreciated.

Thank you

[JacobZ]

Hi @adnanqureshi,

Yes, you should remove the concrete that you've added to block the gaps. There will be two distinct concrete masses that are not interconnected so it should be easy to remove. I'd suggest doing it from the outside as there is less potential for you to hit the slab or the shed while carrying out the demolition work.

Once the concrete is removed, follow the same steps that I advised earlier to fill the gap where the corrugated sheets run past the edge of the concrete.

For the side where the sheets sit in a channel on top of the concrete slab, simply run a bead of the same Sika 11FC along the bottom edge of the corrugated sheets and the channel that the corrugated sheets sit in.  

Seal the underside of the channel will stop water getting underneath, which I suspect is the issue. Running a solid bead of Sika 11FC the full length of the shed will stop the water getting beneath the channel. 

You might like to have a look at How To Silicone a Gap for some advice on this.

Make sure you keep a bucket of water, and some rags nearby to assist with cleanup and smoothing the bead as it can be a bit messy if it's your first try.

Let me know if you have any other questions.

Jacob

[Noyade]

Hi @adnanqureshi 

I'm sure @JacobZ has a better grasp of what's going on than me - but to my eyes, especially the external grassed areas - the slab looks too low?

Either that or my father deliberately made me stay on the cement mixer too long when we raised my shed slab in 1990. You can see the 1947 level.

K Mart boot for scale...

[adnanqureshi]

Thank you, Jacob, for this clarification. I have one more question sorry so i can look into it the way you are explaining, when i am sealing the underside of the channel should i do it from inside or outside.

In addition,when i using the foam and Sika 11FC to put in the channel and seal i have noticed the foam is big and channel is small to insert the foam in.You can notice in the picture as well there is a foam already but i havent put Sika 11FC though.

Kindly refer to photos below. Thank youThis is foam insert and should i then put Sika 11FC here or use Sika first in the channel and put foam on itThis is outside the shed under the channelShould i put Sika 11FC here which is inside the shed under the channel.

[JacobZ]

Hi @adnanqureshi,

There's no need for the foam inserts on this side of the shed where the channel has been used. They are only needed where the corrugated sheets run past the edge of the concrete. They are only intended to act as a backing material to keep the Sika 11FC in place.

You should seal the bottom edge of the channel from the outside where you've highlighted in your second image. If you seal it from the inside, the water will be able to get underneath the channel but will be blocked from getting into the shed. This will allow the water to sit underneath the channel which can cause problems over time.

Let me know if you need any further clarification.

Jacob

[adnanqureshi]

Hello Jacob,

Thank you very much for all this explanation.Just one more question please,should i fill the gap where the corrugated wall is sitting on the channel itself as shown in the picture.When i will use Sika 11FC under the channel the gap between the corrugated wall and channel will be still there isnt.To fill it should i put Sika 11FC as well.

In addition,i do remember that you have mentioned to use foam and Sika 11FC to fill the same gaps on the all four sides of the roof.Is there any recommended way like how to use foam and Sika 11FC.Should i first put Sika and then use the form on it so it can stick together? Or should i use something different on the roof/ceiling.

Thank youRoof/Ceiling gapsGap between channel and corrugated wall from insideGap between channel and corrugated wall from outside

[JacobZ]

Hi @adnanqureshi,

You can seal any of the gaps that you choose to. 

I mentioned underneath the channel as it is the likely point of water entry, so this is the most important gap to seal, but if you wanted to take the time and expense to seal everything it would certainly be worthwhile.

The Sika 11FC can also be used to fill the gaps between the roof batten and the roof sheet. I'd suggest running a bead of the Sika 11FC along the top contoured edge and the flat bottom of the foam filler. Once you've applied the two beads, push it into place in the gap.

Keep in mind that this stuff is extremely sticky, so make sure you have a bucket of water and plenty of rags nearby to clean up if it gets somewhere you don't want it.

Let me know if there's any further questions.

Jacob