Steel Roof - damp ceiling edges on the non drip lining

Sniipe

I have a well ventilated shed however the non drip lining towards the walls are wet in patches. Below is a crude side on view of it. Its becoming so damp that its dripping inside. I've recently used an angle grinder on the roof edge to make it sharper to stop water from pooling at the bottom (there was a slight lip). The water is not coming through the self tapping screws.

I was thinking of installing DPC underneath by: lifting the roof off and have it taped onto the non drip lining about a foot up (which is higher than the current dampness area) and having it come down almost as much as the leaf guard.

cjpm

Are you sure the non drip has been burned back an adequate distance? It’s not clear on your photos. My builder burned off the last 4” of the coating to ensure that the capillary action wouldn’t occur.

cjpm

https://www.boards.ie/discussion/comment/121341254#Comment_121341254

That’s your problem so.

Hope they aren’t 25’ long sheets 😭

dohc turbo2

Don't know that but I know roofers put it on both ends at the start , stops it going damp and black looking

Lime Tree Farm

Screenshot_20231106_132327_Adblock Browser.jpg

Check the measurement of the burnback overhang.

Sniipe

Overhang approx 50mm

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Inside view approx 100mm

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Height: 40mm

Sniipe

The non drip is right to the edge. Perhaps this is the missing part. I will look into taking the sheets off and burning the last 4" off.

dohc turbo2

That stuff pulls in the dampness, brush on a varnish to the ends to stop it travelling in

Sniipe

That would be a heck of a lot easier than taking them off and blow torching them. Do you reckon I could just paint the underside ends?

Sniipe

I opted to do it right and took the roof off and started scoring it with a blade then peeling it off slowly. Followed by a blow torch to finish it off. I've half done today - big job. Hopefully it works out. I will for sure update here and thank ye all.

Sniipe

Half the shed was done yesterday. After a wet night it seems that the non drip surface is dry inside. This almost fully confirms that the capillary action did not occur.

Thanks cjpm for your advice. I will confirm fully after we've had a wet and windy night.

Sniipe

I did the other half on the weekend and I'm very pleased with the results. A mammoth task but defiantly worth the effort. Thanks very much to everyone who helped especially cjpm. A dry shed makes a happy man :D