How to water-seal edges of an Absco garden shed?

[bennyboy]

Hi, I constructed an Absco 3m x 3m garden shed on an existing concrete slab as a DIY (totally new to DIY, and highly inexperienced). With the build complete (sparing a few minor issues), I am now looking for steps to seal the edges of the shed, so as to prevent any water ingress when it rains. 

Absco recommend the shed be built with the edges on a recessed concrete slab to prevent this, which wasn't an option as i wasn't sure which shed i was getting when the slab was laid years ago. Question is, how do i seal the inner edges of the shed? 

Some pics of the shed and issue attached, looking for inputs from the community. 

Shed on slabFront entryLooking towards the rear of shedRear right corner, exposed side

[bennyboy]

@CSParnell @EricL Here's a quick update.

I had a look this morning, and can see what is the possible cause of the water ingress. 

Gap below frame

Sealant applied

Sealant appliedSealant applied

I suppose I shall consider sealing the channels following results from the next rain, as that would require a LOT of sealant.

[Remarka6le]

Hey @bennyboy , 

I installed a similar yet smaller shed when we first purchased our house, it's great that you've done this as soon as you've built it so as to not be impeded by anything, but if I could do things again, I'd have sealed the channels right from the start. Trust me when I say it is worth the extra effort and sealant, you also wouldn't have to clean out as much gunk (and other various things) if you did it from day 1. Loving the results btw  

[CSParnell]

Great work that should definitely keep it at bay.

[EricL]

Hello @bennyboy

Thank you very much for posting those photo updates of your shed. It looks very well sealed, I think that should be sufficient to keep your floor dry.

Eric

[bennyboy]

Tagging @EricL  and @CSParnell for their attention. 

We had some good rain this morning, which was a good test for the sealant work i had done over the week at the inner bottom edges of the shed.

Most of it has held well, with the only signs of dampness being around the anchor bolts in the concrete, which makes sense as there was no sealant around the region where this meets the shed edge. Probably not a major issue in the grand scheme of things. 

Dampness around the anchor bolts

Dampness around the anchor bolts

However, where I'm facing an issue is the water ingress from the region around the doors. I suppose the design of the doors doesn't do enough to prevent the water collecting at the bottom of the door channels and making its way into the shed, overriding the sealant applied to the bottom of the door jambs. I also suppose the gap below the door may also allow for water to make its way in to the front of the shed. 

Open to suggestions from the folks here. 

Water ingress at the front of the shed

[Remarka6le]

@bennyboy A small guttering system on the front section of the shed may work? I know member pstq did something similar with his shed and that seemed to work. 

[bennyboy]

@Remarka6le , what a find.. that is the exact same shed model! 

Certainly does look like a design oversight, more of an issue if your shed front tends to get a fair copping of rain. 

I don't reckon i have the skills to chop the door height as done by pstq, so need to see what other ways are possible to resolve this. 

[MitchellMc]

Hi @bennyboy,

We'll need to determine exactly how the water gets inside to devise a solution. Does it appear that the rain is running down the outside of the door, filling the bottom channel of the door frame and then flowing over the back of it and inside? Those bottom door channels have a higher and lower side. The lower side goes to the exterior, allowing the filled water to go outside instead of inside the shed.

There should be a 20mm overhang that will allow water to escape the C channel roof capping without running down the wall. It sounds like the roof might be misaligned, causing the roof sheeting capping to touch the front walls capping. Have a check to see how much roof overhang you have on the back of the shed. The roof is misaligned if there is more overhang on the back than the front. There should be around 20mm on either side. If the roof capping touches the wall, water will run through the top of the wall or doors. If the roof ridge beam was installed off-centre, then the roof sheets will be too, causing this misalignment. You'll need to shift the ridge beam and sheeting into the correct position to stop the water ingress.

Failing to identify the issue, if there is a big enough gap under the door, I'd suggest pop-riveting an L profile onto the bottom frame would help immensely. That way, anything that runs down the door should be pushed back outside by the profile. I've created the below image to illustrate.

Please let me know if you have any questions.

Mitchell

[bennyboy]

@MitchellMc thanks a lot for your reply and taking the effort to illustrate the same. 

I had a look at the door channels, and they are indeed high side outside, which as you mentioned is incorrect. I do remember doing it this way just for doors, but went back to check the video from Absco to see if this was mentioned there, and no, it isnt. I'll have to swap these the other way for sure, as you mentioned. 

In addition, i also checked the alignment of the rood capping to the front wall capping, and it does look like they touch, which could explain the ingress/flow from here, I will need to double check this once again when it rains, to confirm this is what's happening.

I believe the L profile installation will be a good option once i have checked out the other suspects as above. 

Thanks once again for your help. 

[EricL]

Hi @bennyboy

It's a solution worth exploring, if the gap can be covered with the "L" profile channel then there will be no need to attach anything else to the shed. 

Please keep us in the loop, we look forward to hearing the results.

Eric