Difference between revisions of "Guttering"
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Revision as of 17:26, 11 February 2009
Why have Guttering?
Gutters direct roof runoff away from the house foundations, and prevent it splashing onto walls as it falls to the ground. Thus 2 causes of damp are removed.
A very few houses don't need gutters. Examples are pole suspended buildings, where ground splash will occur below the level of the building.
Decaying vegetation builds up in gutters and hoppers, reducing water capacity, then blocking them altogether. Neglecting gutter cleaning may result in interior wet patches on upstairs walls, exterior staining on walls, and in some situations can rot flat roofs. (The latter can occur where a gutter draining a pitched roof blocks, and the water lands on an adjoining lower flat roof.)
Single storey house gutters may be cleaned with a garden trowel.
2 storey house gutters may be cleaned with a J shaped copper pipe pole with a flattened top end to give a water spray.
3 storey house gutters may be cleaned with ?
On old houses with open drains and hoppers, the drain grates and hoppers need clearing too.
Many types of gutter rely on paint or bitumen to prevent corrosion and failure.
Plastic guttering is prone to joint failure due to rubber seal deterioration, and due to pulling apart from thermal cycling.
Porous gutter types such as stone rely on lead lining to prevent wetness and freeze-thaw cycle deterioration. Lead linings don't last forever, and relining is needed when the lead pinholes, creating interior wet patches.
Plastic guttering has the shortest life expectancy of all types due to eventual degradation of the plastics used (although modern plastics may be better than those in use a few decades ago). Its low price and ease of installation has made it very popular.
The plastic becomes more brittle at low temperatures, and in locations prone to heavy snowfall damage may occur due to loading if the gutter sections are not adequately supported.
Plastic gutter expands in the sun (sometimes making creaking noises). Connecting fittings are designed to allow for such movement, and it is important when fitting guttering to allow for this movement in cutting lengths: the colder the weather when fitting the guttering the shorter it should be cut to allow for expansion when hot (and vice versa). If cut too long expansion will cause strain on the fixing screws of fittings and/or bowing of gutter sections. If cut too short lengths may pull away from their sealing strips at the fittings causing leaks.
Iron gutter can last for over a century, and is the most common originally fitted gutter on Victorian houses. Some iron gutter from the 1800s is still in service, although 1930s gutter can be past end-of-life.
Iron downpipes tend to rust through before the gutters, since they are less ventilated. Iron downpipes have a habit of rusting through on the back first, while the sides and front look healthy. An inspection of the guttering system should include a check for this if the house is a century or more old. This can be very difficult to see, even when looking deliberately. A quick feel with a tough glove does the job.
Gutter sections can be deceptively heavy, and caution is needed in removal. Some iron guttering is much too heavy to handle single handed, while some is not.
Iron gutter is heavy enough to kill or cause serious injury and guttering found hanging at an unhealthy angle should not be neglected.
Iron gutter is still in production, and is not as expensive as often assumed. If you're keen to have a gutter that will never need attention in your own lifetime, iron is the prime candidate.
Iron gutter can not be fitted single handed. Trying to fit iron gutter using ladders is ill advised, the things are just too heavy. Scaffolding and a minimum of 2 people are required for safe working.
The traditional jointing compound is lime putty. This usually lasts the life of the gutter.
Iron gutter lasts much longer if recoated with bitumen or paint when necessary.
Aluminium gutter has become more popular on prestigious new builds in recent years. Aluminium gutter is custom made to suit the building. This gives it a very neat appearance, with the minimum of joints.
Aluminium is more robust and longer lasting than plastic. Being custom made it is also a lot more expensive.
Aluminium gutter has not been around long enough for time to tell, but it seems likely that it will not last as well as iron guttering, which is still in production.
This is used as a replacement for cast iron. The weight reduction is useful where access for replacement is difficult.
Wooden gutter has a life expectancy of around 70 years if suitable timber species are used with a leachproof preservative. Some species with shorter life expectancies are also used.
Correct choice of wood species is necessary. Non-durable timber species are not suitable for guttering, and would have very short life if used.
Wood gutter is traditionally unpainted. Painting increases drying times after rain, and can cause rot. Bitumen lining is also used.
There are 3 common forms of wood gutter.
- \/ shaped gutter, formed by nailing 2 planks of wood
- \_/ shaped gutter formed by nailing 3 planks of wood
- Moulded gutter profiles formed from a single piece of profiled wood. These may be half round, ogee, or other shapes. When painted these are easily mistaken for iron gutters.
Wood gutter is considerably more robust and more durable than plastic. Wood gutter is not particularly expensive, and lasts well if designed properly. Some believe it deserves wider use, and that its decline in popularity owes more to popular misconceptions about maintenance than anything else.
When replacing wooden gutter on historic buildings, it is generally found that fitting plastic causes a sizeable change in appearance & character, and replacement with wood is generally recommended.
Annual cleaning of wood gutters makes more difference to life expectancy than with other types.
Species used for timber gutters:
- Scots pine, Pitch pine
- Sweet chestnut
Galv steel gutters are robust and available in larger sizes. They are used on commercial developments, where durability and vandal resistance are important.
Deteriorated steel gutters can cause heavy staining.
Non-galvansed steel gutter has much shorter life expectancy.
Not a popular type of gutter, expensive and a temptation to thieves. In time it becomes green. Runoff from copper guttering should be drained away remotely, as copper compounds can kill plant life.
Stone gutter is generally built into the structure of the building, and lead lined. The lining needs replacing eventually when holed, otherwise wet areas appear, and stone begins to deteriorate due to freeze thaw cycles. [[[[ == Do Not lead line stone gutters ==]]]]
Needs no painting or routine maintenance. Can become brittle with age.
Available in a variety of colours.
Some buildings need gutter joining at other angles than the popular 90 and 135 degrees. Discussion
- Adjusable angle joints are available, but expect to pay £20 or more each.
- Custom angle joints are also available, but cost more.
- Joins of any angle may be DIYed by cutting 2 short lengths of gutter and gluing with PVC cement.
Since each guttering set is custom made, the company will take care of this as part of the job.
Any angle join is easily made in wood.
- Jewson's, York
- Discussion of species
- Redwood gutters
- Howarth Timber (Austin) Ltd 0161 652 5421
- Illingworth Ingham (MCR Ltd) 0161 368 3881
- More about gutter joints & drip prevention, what works & what doesnt
- Painting info
- Perhaps some idea of costs.
- Pics of detailing of the gutter types
- Steel gutter section
- Wood species