It's true to say that gutters don't get the respect and admiration they surely deserve. After all, without them rainwater would simply pour off every edge of the roof, leaving a soggy mess all around the house and probably saturating the walls in the process.

But if gutters are doing their job properly, water is safely channelled towards a downpipe and into the ground-level drainage system, thus saving you the horror of having to deal with damp walls.

Although this remarkably low-tech-yet-efficient system pretty much takes care of itself, the odd spot of maintenance is nonetheless essential.

If leaves, dirt, twigs and other debris get washed off the roof or blown in by the wind, a blockage can occur, which means the system won't work as well as it could. An annual inspection and a good old prod with a scraper or trowel should stop material blocking the flow.

At the junction of the gutter and the downpipe, place a crushed ball of chicken wire at the outlet, to help prevent further blockages in the downpipe. Use a stiff wire to clear an angled pipe, pushing downwards from the top to dislodge the blockage.

If the downpipe itself is blocked, use drainage rods from above and push downwards to remove the blockage.

Blockages are not the only things that can cause overflow to occur though, so if you're baffled as to what the cause of the problem is, check the line of the gutter to see if it is level. It may be that sagging is occurring, forcing the water back on itself, in which case the brackets, or the screws on the brackets, might need replacing if they have perished.

Also check that the gutter is sloping towards the downpipe, not away from it, and reset the bracket at the outlet end to a lower position if necessary. The other end can be slightly lifted by placing a small strip of lead under the gutter, between the bracket and gutter.

Cast-iron guttering is often present on older properties and, on the whole, it's pretty robust, provided you paint it regularly to prevent rusting. Prime the insides with zinc chromate paint and use bituminous paint for the finishing coat.

Because cast iron is heavy, it is particularly important to keep an eye on the fastenings, to check they aren't buckling or looking a little worse for wear.

It is also important to seal the joints to prevent leakages.

If water has been seeping through the joint for some time, the joint is probably too rusty to unbolt, in which case you can use a hacksaw to remove the bolt, then drill out any remaining pieces.

Use a chisel to lever the two sections of gutter apart, then remove the perished sealant by scraping it away. Clean the area with a wire brush and apply fresh sealant. Then bolt the two sections back together again, using a new nut and bolt, and remove any excess sealant seeping from the joint.

Finally, paint the inside of the gutter using the method mentioned above.