The difference in position between the two is known as the gutter fall.
Minimum gutter fall uk.
This applies to general roof areas along with any internal gutters.
According to bs 6229 bs 8217 flat roofs should be designed with minimum falls of 1 40 to ensure a finished fall of 1 80 can be achieved allowing for any inaccuracies in the construction.
The gutter flow rate chart below compares the specific flow rates for each floplast gutter system.
To ensure the rainwater is directed towards the gutters the sides of the roof surface apart from the gutter edge require a minimum of 50mm upstand verge provided using triangular pieces of timber called tilt fillets nailed to the edges of the decking not to the wall.
If your outlet is situated in the middle of the fascia repeat this process at both ends.
Have a minimum width of 300mm for commercial installations 200mm for domestic installations.
Box gutter outlets must discharge through either a rainhead or sump.
Before you jump into a diy gutter installation consider hiring a professional to hang your new gutters properly the folks at harry helmet have over 30 years of experience in this area and they ll install high quality seamless gutters that are affordably priced and come with a 20 year warranty.
Have a minimum depth of 75mm at the high end.
The numbers on the left hand side of the table show the flow rates when the gutter is fixed level no fall and the figures on the right detail the flow rate when the gutter is fixed to a fall of 1 in 350.
Comparing floplast gutter flow rates.
Calculate the gutter slope by dividing the length of the gutter needed by 10.
Your gutters have a high point and a low point.
The gutter slope also called the pitch is the amount the gutter tilts down to let rainwater flow out of it.
Overflow box gutters must have independent overflow provision discharging to the atmosphere.
If gutters slope too severely they don t hold water and water could splash over the sides in heavy rain.
The high point is where the highest gutter bracket is placed and is the furthest from the outlet s.
Position and fix a fascia bracket at this point ensuring that it is higher than the outlet and the fall to the outlet is about 3mm per metre.
If the run has two downpipes then the high point should be placed between them.
If the length of the gutter is 10 5 metres 35 feet the amount of slope required is 1 25 cm 1 4 inch multiplied by 1 metres 3 5 feet which when.
The amount of collected water increases until it spills over the sides of the gutter.
The minimal slope needed for proper gutter drainage is 1 25 cm 1 4 inch for every 3 metres 10 feet of gutter.
All gutters and downpipes should be accessible for maintenance.
