Valley gutter lining - what should i do?

[nalakitty]

We got keys to our new house last month and found out the valley gutter is uneven and leaking. Nothing was picked up in survey. surprise surprise 😂

Recommendations from roofers (it must be a slow market as we are able to get quite a number of responses) range from fibreglass, felt, lead to monoseal. ive discounted fibreglass as its not really durable. Do you have experience with any of the others? And how much did you pay?

Adding a couple of photos here. Good day vs rainy day. Standing water. Not draining well because of lack of gradient. Please help!

The lack of gradient is a problem whatever you use. I think you need to get a recommended roofer and get their opinion. For better graded gulleys I'd say lead, unlesss it's an area of high crime where it might get nicked, but I really don't know what would be best there.

(we've had lead for our new gulleys, but part of a re-roof so I can't suggest a figure for the cost)

Why is it all odd angles and the wall skewed?
How did the roofers explain how they’d solve the problem with the gradient and wall?

the house was not built well (one of those cheaply built new builds...in hindsight) and the previous owner did not do a proper job in getting it watertight. The gutter is made up of different pieces of metal. And the joints have been worn out by weather and possibly were not laid well in the first place so the whole thing is now bumpy. plus there is only one drain outlet.

We have got all sorts of recommendations from roofers (from checkatrade, masterbuilderassociation) that i have no idea what would be best.

One surveyor (the one that did the house survey. i did call him to to report this issue after we got the keys) suggested lead. but given the length of gutter and the lack of height in ours, a roofer said its not easy to create a gradient. A second one said to do it properly we need to remove the roof (which is a metal sheet), get the lead lining in and then put the roof back. The third one said whatever we do he will not give us the typical guarantee (not that its worth anymore coming from the roofing company not insurance) as the lack of height in gutter (we dont have the 150mm required) means he cannot do a proper job.

Torced on felt was recommended by two roofers and agreed by a surveyor friend of mine.

Another roofer said we should use monoseal. after some googling, i found out its brand of liquid rubber. This roofer doesnt work with this and cannot get our business so i think/hope he is more impartial as a result.

We will probably never get the gradient we need and have to accept that there will always be some standing water. Right now am trying to work out which solution is best at preventing leak.

Is it a self build? I’m amazed it’s a new build. It looks terrible, I’m not surprised one won’t give a guarantee.
I’d say use lead, as once it’s in you won’t need to replace it, however the conundrum is the odd parapet wall not having an overhang, they may want to install the lead valley, then a tin/copper/whatever covering over the full length of the parapet.
It’s a terrible design, I thought it was a barn or industrial conversion.

Also, what is actually under the existing valley? What is it sitting on? The original roofers must have been cowboys to install it like that, unless there are reasons they couldn’t overcome.

You really do not need a massive fall, but you need to make sure there is some fall, no matter how slight.

the valley is not sitting on anything. It is attached to the bottom of the roof. Or maybe it is sitting on the external wall, or part of the wall. I cannot tell for sure.

From land registry search, looks like one individual got hold of some land. former warehouse or some sort. he then divided the plot into several pieces and partnered with different builders.

Its not a self build. But probably done by an amateur builder.

So lead valley is not enough? Will need a lining? Im not sure if i understood what you said about covering it with tin/copper @C4tastrophe

How long is the gutter to the outlet ? Im guessing if they need 150mm fall then it’s probably about 15m ?

it should be just 7-8m. i thought the 150mm was standard. was mentioned by two different roofers. One made the comment just based on photos.

What I mean is usually the lead would be lipped into the wall on the left. As that is ‘impossible’ I’d expect the roofer will want to make the valley out of lead, and then either add coping stones on top of the wall, like at the far end, or add a copper ‘lid’ over the wall that also covers the upright side of the lead.
For 8m you don’t need 150mm drop, 50mm would do. If the valley is deep enough it will still drain quicker than it will fill, especially if the valley goes up high enough under the roof.

Wall - blue
Valley - red
Roof - yellow
Coping stone/parapet cover - green

Thank you for the diagram! So the left side is sorted. The challenge now is how to tuck the lining under the roof without actually lifting that one big piece of aluminum.

Plus how to get my neighbour on board. Its two houses there in the photo. We share the same roof, the same gutter. Theres no sign of water ingress their side. I am hoping quotes from roofers will not be too crazy.

@nalakitty

Why do you think fibreglass is not durable.

It's used in many cars and motorbikes bodies.

A few roofers did recommend fibreglass. But they never came in person. They all say its easy to fix with fibreglass. We have got two surveyors look at it and the verdict is its not going to be simple. And most of the roofers that took the time to come to the property either just said sorry its not my thing or suggested something else, felt, lead. Thats why i have the impression that those recommending fibreglass dont know what they are talking about or simply want to make a quick buck.

I'm so confused about how this house is constructed, why does it have a tin roof?

Sorry not helpful at all 🤦🏻‍♀️

Metal roofing materials are common and have been used for years.

Here is what i think is the best solution? Its the same as the sketch above but you can a one piece aluminium gutter made that will span the full length on the roof ( no joints ) , the roof would need to either cut all the way along so the gutter goes up behind it are remove the lower part and cut them .

Then aluminium copings go over the wall ,any water when it rains then drips into the gutter as you angle them slightly when fitting.

This way would mean little disruption to the existing gutter ,although some work would need to be done to the wall so the copings could sit level and flat all the way along.

aluminium has about 35- 50 year lifespan and would be cheaper and less labour intensive than lead.

i have used the aluminium guttering ( not in the same way as you ) and it can be made to any size you need. And also the coping ca be too.

im sorry to say that whoever you get to do it wont be cheap ☹️

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Oh no photo ☹️

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Here the type of thing I used recently it’s the smallest size they do but your would need the be wider and deeper due to he steep pitch of your roof.

thank you for the advice @Diyextension

i will ask roofers about aluminium. but whatever the metal, they will all face the same challenge. our roof is one big sheet of metal. not slate. we cannot remove the bottom rows, install the new metal box and then put the slates back. we cannot do the tuck under. am hoping there is some sort of sealant that can bind the edge of the metal box to the bottom of roof.

Sealant of any kind will always be the weak point. Id hazard a guess that the roofing used to drip into the gutter but at some point someone has filled in the gutter with concrete? To seal it ? And have gone higher than the bottom of the roofing sheets ?

That joint where the roof meets gutter just lets water go in between the two.

you need to get the water dripping into a water tight gutter and enough fall to take it away fast enough in heavy rain.

Its a job that needs doing right ,so every time it rains hard your not wondering if your going to get a leak .

I think you could be able to cut along the bottom of the metal roofing sheets a few inch up, remove the piece and get a metal box gutter up behind it.

It might be better in this case to remove the roofing. Cutting it looks like a job and a half.
I still can’t get over the skewed wall, few coping stones, that stick on sheet partially covering the coping stones, and then all the silver sealing paint!
It looks like a weeks work to rectify.