Very early gutters and associated pipework were made from lead. This was later almost universally replaced by cast iron and again over the last twenty years or so this has totally changed to plastic which is easy to secure, light to carry and support, and needs no maintenance. Aluminium guttering is also available from specialist firms who often make the guttering on site.
Cast-iron guttering is generally fairly durable but it can rust and is rather brittle. It should be protected with a coat of gloss paint on the outside and a covering of bitumastic paint on the inside. If corrosion has perforated the metal, you can make a temporary repair using a mastic sealant or a polyester resin.
The joints in cast-iron guttering are made by placing putty between two adjacent lengths of gutter and then clamping them together by using a small nut and bolt. In time these joints can fail but they can be repaired by unscrewing the nut and bolt, scraping the jointing surfaces clean, spreading a mastic jointing compound across the surfaces and finally clamping the two sections together. If the nut and bolt have rusted, remove with a hacksaw and fit a new one.
Cast-iron work in bad condition should be replaced by one of the more modern materials. It is generally wise to replace all the old cast-iron guttering, although plastic gutters can be joined to old cast-iron ones. A variety of shapes and supports for plastic gutters and pipes is available to suit most houses. Always support plastic guttering at regular intervals – as specified by the manufacturer – otherwise it can bow and sag and water may overflow.
All guttering should be inspected periodically to make sure that it has not become blocked by leaves or silt washed from the roof. Use a trowel to get the rubbish out. If the trouble occurs frequently, it is worth fixing guards into the gutters. You can buy these or use pieces of wire or plastic netting bent to a half-round shape and jammed in the guttering so that they spring out and hold themselves in place. A down pipe can be unblocked by pushing a long stick down it – you may have to undo some of the joints and reseal them again.