guttering

Dont waste the planets resources replacing the whole gutter for the sake of a couple of pounds worth of replacement seals

-Dont waste the planets resources replacing the whole gutter for the

-sake of a couple of pounds worth of replacement seals

Once the guttering has been subject to uv degradation and embrittlement, changing the seals can be a problem (if you can get them). OTOH if they are not leaking now, leave well alone until they are - if they do leak it will start very slowly (drips). You can always pop some mastic in them, get a few more years out of them and then change them. I suspect you are over-worrying!

From someone who does have the odd joint in plastic guttering that is dripping slightly, what is the best way of applying some mastic. Obviously a bit of cleaning up but do I need to spring the joint and get the mastic into the joint ?

Thanks Rob

Why does this ring "touting for work" alarm bells?

"If it ain't broke, don't fix it".

Depends on what type of gutter seals they are, if they are the flat sponge type, then it=92s a complete renewal of the joint unions. But if they are they are the type that fit in a grove, then you only need to replace new rubbers.

Because plastic gutter expanse and contracts, mastics or other glues don=92t work well as they pull open.

Springing the joint and putting it inside would be the best - as someone else has said, it does tend to move, plus the inside gap is full of cr*p. Sometimes, springing the joint and cleaning will improve things (assuming that springing the joint doesn't cause something to snap - they will be much more brittle than when new) and applying silicone grease. If you can get replacement seals that's the best but I haven't come across any for sale. You can also try car underseal etc. Yes it's a bodge but it may buy you another year and, if you are going to replace in the end, what's the problem?

Springing the joint often snaps a plastic supporting bracket, rarely the gutter itself. So long as you have a couple of spare brackets ready beforehand and you're up there anyway, it's really no big deal.

Use a low modulus mastic though - there's a lot of movement in those joints.

I know Hunter for one do 5m lengths but

o I've not seen/used them o you may have to get them ordered specially. o some argue against such long lengths because of the greater thermal expansion at the joint(s)

Or there is continuous aluminium if you can afford it: ISTR claims for up to 30m continuous lengths!

neverwas coughed up some electrons that declared:

I presume that's formed on site out of a roll - seem to remember seeing something like that?...

Seamless guttering.

It comes off a roll and is pressed on site (ie back of a van). The operator sets the maching to mould the desired shape of the guttering.

Very impressive to watch.

Adam

Contrary to popular myth, the more joints you have, the less chance it has of ever leaking.

As has already been mentioned elsewhere in this thread, guttering expands and contracts - a lot, and if you have a 5m length, you are going to lose at least 50mm of this in winter, and as it pulls itself through the joint, it drags out the rubber seal underneath. Given that each piece only usually overlaps into the joint and at outlets by about 50mm, after a season or two, the seals are mangled. If you use shorter lengths, say 2.5 or 3m and more joints, you are giving the gutter more space to expand and contract without displacing these rubber seals.

I recently bought some galvanised steel sheets for the garage roof. Went to the supplier and watched them form them - unrolled from a large coil, both sides sheared off to make the correct width (the waste being re-rolled for disposal) and then pulled through the rest of the machine, with each ridge starting to be rolled at a different point, a second roller for each ridge to form the final shape and a big guillotine to automatically chop the set lengths.

They were dead cheap too. I got the impression that they were actually machine repairers and refurbishers and their client had supplied the steel for testing purposes!

SteveW