Cast Iron Rainwater Goods - What Mastic? & What Fixing?

[Roger H]

Hi.

A few questions on cast iron rainwater goods. I've a situation where I need to reach a secondary hopper 45cm away from the main hopper - I'm guessing that I make the connection via a lazy 's' shaped spigot and an elbow. These fittings don't seem to have much in the way of lugs to fix them to the wall. In fact, among my cast iron bits and pieces none of the smaller junction bits do. But they will be heavy. Are they meant to just rest their bottom end in the hopper or has anyone a better suggestion? I'm thinking I'm needing an intermediate fixing.

Secondly, has anyone come across a part that allows a male end of a downpipe to connect with another male bit of downpipe? (the lugged head portion was sawn off and used elsewhere alas and I now have a 2.5m ‘orphan’ bit of pipe).

Finally, what mastic or filler is best between the joints on downpipes - mine are a bit rattley...

Thanks in advance of your advice.

 

[MatthewC]

You're about two weeks ahead of me, so I'm not sure of the answers but have been doing research online. http://www.gutterworks.co.uk have lots of offset pipes which sound like the answer for your first question, and none of those illustrated have any attached fixing for the pipe, even if they are offset by over 500mm. They also have things called "Sockets with ears" which you can find on the last page of "Circular Pipe Fittings". These look as though they will either answer the first or the second question - I suggest you ask them via their website.

 

[Roger H]

Spot on Matthew. That's saved me about £100 and let me reuse 2.5m of downpipe that was destined for the tip.
Gutterworks guys extremely helpful.

 

[Feltwell]

J & JW Longbottom are great for all sorts of obscure fittings, and are very helpful.

http://www.longbottomfoundry.co.uk/

Saint Gobain Classical Rainwater range can be found through most builders merchants - much cheaper than their own website (which is rip-off!) - they do a downpipe head to use an off-cut of plain pipe as you describe.

You can attach pipes to your wall with nail-in pipe clips, ask Longbottoms, they do them.

You don't normally need to seal the joints, in fact it's a good idea not to - if you get a blockage it makes it easier to see where it is! If the joints are rattly some Roof and Gutter seal would do the job, but no need to seal it completely. I've also used little strips of roofing lead to do this, folded into an S shape and gently tapped into 3 sides of the join with a small cold chisel.

http://www.screwfix.com/prods/67521...s/No-Nonsense-Roof-Gutter-Sealant-Black-310ml

 

[d49xc]

I've always used putty to seal between the downpipe joints and likewise to seal between the joints of adjacent gutter sections which of course are held together by the gutter nut/bolt.
It doesn't have to be stuffed too far down as getting it out again in 50 years time when you need to remove a section is rather difficult as I can attest on several occasions.
I just think the sealed downpipe joints when all painted over look much better than leaving them free.

I agree with the recommendation for Longbottoms.
I've got several replacement imperial sized manhole covers off them - fitted the existing frame almost exactly - though they are not guaranteed to do that.
First class firm.

 

[Penners]

Putty is probably much more traditional and authentic, but frankly I'd prefer a modern mastic for this job, such as that mentioned my Feltwell. Putty will eventually dry out and crack. A silicone mastic will, IMO, be much more reliable for a much longer period. I see nothing detrimental to the building in using it.