Roof Problem

[zyklon]

Purchased a farm not long ago and there is a lean to cattle shed which has spaced roof sheeting. It was done a few years ago so still looks like new.

Only problem is, when it rains especially heavy rain, it floods the cubicles below. Couldn’t understand but looking closer at the corrugated sheets, the edges are wrong. The wrong sheets were used for spacing and the spacing is a tad wide.

Anyhow, without replacing the whole sheets and doing away with spaced sheeting, is there an alternative I could do to solve the problem or would I be best to just strip it all off and replace even though the sheets are as good as new?

 

[Dry Rot]

Could you cut (new) sheets lengthways, overlap existing, and screw into position leaving a narrower gap?

 

[Kildare]

That roof is doing more good than harm. A drop of rain won't harm cows

 

[Dry Rot]

On reflexion, I agree with Kildare but sitting in water isn't a good idea, so maybe sort the drainage out?

 

[zyklon]

That roof is doing more good than harm. A drop of rain won't harm cows

Not good when they have to lay on wet sawdust.

 

[franklin]

Having seen similar in the thread on suckler buildings, it looks like it was done on purpose for ventilation.

 

[Ukjay]

Now before I say this, I know it is not the done thing, but in this case where the gaps are a concern as they let the wet in - could you just add guttering under the gaps - this way, you keep the ventilation, but can guide the water to an outlet?

 

[Nearly]

Now before I say this, I know it is not the done thing, but in this case where the gaps are a concern as they let the wet in - could you just add guttering under the gaps - this way, you keep the ventilation, but can guide the water to an outlet?

Beat me to it.

 

[Forever Fendt]

If you don't want the gaps take the screws out lap them as intended and buy a few extra sheets for the end

 

[zyklon]

They are nailed so it would be a grinder job but looks like that is the way it’s gonna be done.

 

[Nearly]

Best way to take out drive nails?
Mole grips or something more high tec?

 

[Goweresque]

I'll admit to knowing nothing about spaced roofs, but to my way of thinking shouldn't the sheets be upside down to work properly (ie the other way to how they would be if put on overlapping as normal)? If the edge of each sheet folds down towards the gap, then you've not just getting rain that goes straight through the gap, you're getting all the rain from the mid point of the first ridge on each sheet either side of the gap. Its effectively a gap of 6 inches (assuming the actual gap is about 3 inches). The other thing is that those wooden purlins are getting a lot of water on them, how long will they last?

 

[Pan mixer]

I'll admit to knowing nothing about spaced roofs, but to my way of thinking shouldn't the sheets be upside down to work properly (ie the other way to how they would be if put on overlapping as normal)? If the edge of each sheet folds down towards the gap, then you've not just getting rain that goes straight through the gap, you're getting all the rain from the mid point of the first ridge on each sheet either side of the gap. Its effectively a gap of 6 inches (assuming the actual gap is about 3 inches). The other thing is that those wooden purlins are getting a lot of water on them, how long will they last?

It was all the fashion a few years ago to do a cattle shed roof like this, upside down sheets and a gap between.

Be a real PITA to change it as every sheet will have to be turned over and mitred and there would be breakages.

Might be a new roof job.

It shouldn't let much water in if it is done correctly, as said above is there a drainage problem in the shed?

 

[mo!]

I'll admit to knowing nothing about spaced roofs, but to my way of thinking shouldn't the sheets be upside down to work properly (ie the other way to how they would be if put on overlapping as normal)? If the edge of each sheet folds down towards the gap, then you've not just getting rain that goes straight through the gap, you're getting all the rain from the mid point of the first ridge on each sheet either side of the gap. Its effectively a gap of 6 inches (assuming the actual gap is about 3 inches). The other thing is that those wooden purlins are getting a lot of water on them, how long will they last?

My uncle has a spaced roof shed and it was done properly, sides cut off the sheets at the factory so that the spacing is the same as a normal roof. It should have the sides pointing up so that very little rain comes in.

Buy yourself a decent pair of molegrips and crack on. Fit a decent vented ridge while you're on.

 

[zyklon]

That’s the problem. The idiots used the wrong sheets. If they had used the correct sheets, the problem wouldn’t occur and I wouldn’t be in this position.

What about filling the space with that black stuff you use to seal tanks?

 

[Goweresque]

How about fitting a cap down the gap, so rain is shed either side into the valleys of the fibre sheets? Spaced off the purlin a bit so it still allows air to circulate?

 

[Tinman Steels Ltd]

Would you be able to use the expansion joints you get for the big six or steel flashings / strips.

 

[Dry Rot]

Now before I say this, I know it is not the done thing, but in this case where the gaps are a concern as they let the wet in - could you just add guttering under the gaps - this way, you keep the ventilation, but can guide the water to an outlet?

To pinch this idea, a simple solution might be to put the gutter on the upper/outside of the roof attached with tek screws that have a rubber washer. The screws create a water tight join in the valleys of box profiole, so there would be no leakage between gutter and purlin. A cheap and easy fix.

 

[zyklon]

They are corrugated sheets but that half moon gutter would be an alternative.

 

[zyklon]

Would you be able to use the expansion joints you get for the big six or steel flashings / strips.

Not sure what that looks like? Similar to the stuff you use between the joints of a shuttered wall etc?