Gutter join leak sealing

ss2020jd

Would be grateful for any advice from the gutter experts or anyone who has experience with guttering issues!

We noticed one of the horizontal gutters on the side of the house had moved creating about a 2cm gap between the join of the other gutter where water had been pouring through. 

We moved the guttering along so it closed the visible gap and siliconed along the outside of the bracket. 

There is still a drip coming through so I’m not sure if siliconing inside where the gap is would be a good idea? I’ve also seen something about a rubber gutter join so not sure if this would be better.

Attached pic of inside gap left in case it’s helpful. Any help much appreciated. 

Bendy_House

Lengths of guttering expand and contract a surprisingly large amount over the seasons, and even between night and day - you've probably heard it creaking first thing in the morning as the sun hits it?! So, the lengths should be cut to allow for that full movement, whilst still sitting within the part with the rubber seal on each connector. Cut the gutter too long, and it might buckle/bend as it expands to the point it hits the end stops, or cut it too short, and one end will withdraw beyond the rubber seal at one end, and is then unlikely to push back on to it again. So, the lengths need to be the 'right' size, within a certain tolerance!

I suspect yours is fractionally too short.

The gap shown in your pic is small, in fact 'too' tight. That would be caused by either the gutter length being too long (not in your case), or the weather being very hot and the gutter is at full expansion, so is tight like that at BOTH ends (again, not in your case), or else the gutter has been pushed too far one way, and not the other - the 'other' is now at risk of coming short of the rubber seal at the other end (quite likely in your case!)

Silicone and other sealants aren't ideal as the gutter has to be able to move - slide - over the rubber seals, so a better solution would be to remove that length of gutter (it just unclips), remove, clean, check and replace the rubber seals, give the rubbers a smear of silicone GREASE (not 'sealant'), refit the gutter evenly, and then - perhaps - put a blob of silicone sealant on the inside of the connectors, near the ends of the gutter, and up near the top (so it doesn't interfere with flow). I haven't tried this myself, but the idea would be that, as the gutter expands in summer, the slipping end will make contact with the sili blobs, and this will help prevent it going too far that way, so the other end moves instead. Make sense?

As I said, not something I've tried, but if the guttering is so short that is keeps contracting away beyond the rubber seal, you'll likely always have an issue.

If you look inside the gutter connectors, you should see raised ridges that will prevent the gutter end going too far, yes? If you clean them thoroughly (perhaps roughen them too), and apply blobs of sili sealant to them, coming over a few mm towards the gutter end, they should hopefully act as rubbery buffers and even out the gutter movement, and so prevent one end coming 'short'.

Bendy_House

Hang on - that isn't cast iron, is it?

grumbler

IMO, the picture is too obscure, I don't see any gap that is too small allegedly. Is it the view from under the joint? A top view is far more informative.

And yeas, sealants usually don't help  when a joint leaks.

Also, a bigger picture can be helpful. The last section in a row sometimes can gradually move away from the supporting joint between two sections.

ss2020jd

Thanks so much @Bendy_House for your detailed and very helpful reply. Much appreciated and that does make sense. It sounds like an intricate balancing act. 

I’m not sure there is a rubber seal between the joints. I can’t see anything obvious like that or the raised ridges that you mention. Nothing like the ones I saw pictured online . Highly likely they aren’t there as we are discovering many examples of the creative DIY of the previous owners. When you say gutter connectors do you mean the brackets? Or the rubber seals that should be there to connect the guttering? This pic shows the brackets from underneath. Apologies for more questions and my ignorance. Gutter problems are all new to me…

ss2020jd

Bendy_House said:

Hang on - that isn't cast iron, is it?

No it’s plastic. 

ss2020jd

grumbler said:

IMO, the picture is too obscure, I don't see any gap that is too small allegedly. Is it the view from under the joint? A top view is far more informative.

And yeas, sealants usually don't help  when a joint leaks.

Also, a bigger picture can be helpful. The last section in a row sometimes can gradually move away from the supporting joint between two sections.

Thanks @grumbler, the first pic is a top view of inside the guttering. It was tricky to get a good pic. The other pic is the underside. I will try to get a better pic after the rain stops. 

FreeBear

ss2020jd said:

Bendy_House said:

Hang on - that isn't cast iron, is it?

No it’s plastic. 

You can often get replacement rubber seals - Assuming the coupler clips haven't gone brittle with age, unclip, replace the rubber, and reassemble. Give the underside of the gutter a wipe down and apply a thin smear of petroleum jelly before reassembly.

ss2020jd

FreeBear said:

ss2020jd said:

Bendy_House said:

Hang on - that isn't cast iron, is it?

No it’s plastic. 

You can often get replacement rubber seals - Assuming the coupler clips haven't gone brittle with age, unclip, replace the rubber, and reassemble. Give the underside of the gutter a wipe down and apply a thin smear of petroleum jelly before reassembly.

Thanks @FreeBear I can’t see any obvious rubber seals so it looks like I might need to unclip and put them in. 

ss2020jd

Thanks again for all the replies here are a few more pics 

where the drip is coming through from underneath 

stuart45

You won't see any gaskets until you unclip it. There should be a couple of stops inside the union to mark where the gutter should stop to allow for expansion. A new Brett Martin gutter union is only about £3 if you need one, unless it's a fake cast iron type.