BRE Test Report
Testing and comparison of guttering products to the principle of BS EN 12056-3:2000
Prepared for: GutterFlo Ltd
Date: 26 February 2019
Report Number: P114195 – 1000 Issue: 1
Name: Mr Devinder Athwal
Position: Senior Laboratory Technician
Name: Dr Paul Blackmore
Position: Associate Director
This report is made on behalf of Building Research Establishment Ltd (BRE) and may only be distributed in its entirety, without amendment, and with attribution to BRE to the extent permitted by the terms and conditions of the contract. Test results relate only to the specimens tested. BRE has no responsibility for the design, materials, workmanship or performance of the product or specimens tested. This report does not constitute an approval, certification or endorsement of the product tested and no such claims should be made on websites, marketing materials, etc. Any reference to the results contained in this report should be accompanied by a copy of the full report, or a link to a copy of the full report.
BRE’s liability in respect of this report and reliance thereupon shall be as per the terms and conditions of contract with the client and BRE shall have no liability to third parties to the extent permitted in law.
BRE have been commissioned by GutterFlo Ltd to carry out flow rate tests on a Gutterflo gutter product supplied and fitted by GutterFlo Ltd.
This study has been undertaken by BRE as project number P114195 -1001 and is based upon proposal number P114195 dated 18th December 2018.
The products tested were a Gutterflo guard, as shown in Figure 1, designed to prevent debris from blocking gutters without affecting the flow rate of rain water. Three other commonly available products were also tested for comparison with the Gutterflo.
Figure 1 Diagram showing the different configuration of installation and clip arrangement
The Gutterflo gutter product was installed on a test rig provided by Gutterflo. This rig complied with the requirements of BS 12056-3 and was representative of an actual roof with two courses of profiled roof tiles, see Figure 2. The test rig was 4m long and fitted with a 112mm half round gutter with a 68mm down pipe. The testing was conducted in the weather tightness laboratory at BRE.
2. Test programme
The test rig was delivered to BRE partially preassembled. The gutters and down pipe were installed by BRE staff according to the requirements of BS EN 1205-3:2000 Gravity drainage systems inside buildings – Part 3: Roof drainage, layout and calculation.
Initial testing was carried out to establish the maximum flow rate in the gutters without any gutter guards. Testing was then carried out with the various gutter guards to measure the flow reduction (if any). For all tests the water flow rate was slowly increased by 5l/m increments with a pause at each step until the gutters started to over flow.
A total of five configurations were tested, with the first being the base line with no product installed. These configurations are described in the following sections.
2.1 Test 1
For this test the gutter had no product installed. This was the base-line test carried out to determine the maximum water flow rate that would cause the gutter to breach and over flow. See Figure 3.
In this test it was found that the maximum gutter flow rate was 120l/m, after which the gutter started to over flow.
2.2 Test 2
For this test configuration the Gutterflo guard system was installed on to the gutter. See Figure 4.
In this test the maximum flow rate achieved was 120l/m.
2.3 Test 3
For this test configuration a gutter brush product was installed in to the gutter. See Figure 5.
In this test the maximum flow rate achieved was 60l/m. A reduction in flow rate of 50%.
2.4 Test 4
For this test a downpipe balloon was installed over the down pipe and the gutter loosely filled with leaves, see Figure 6.
In this test the maximum flow rate achieved was 24l/m. A reduction in flow rate of 80%.
2.5 Test 5
For this test a rigid type flat plastic mesh gutter guard was used, see Figure 7.
In this test the maximum flow rate achieved was 100l/m. A reduction in flow rate of about 17%.
3. Concluding Comments
Testing has been carried out by BRE to compare the flow performance of four gutter guard products available on the market.
Tests were conducted to the principles of BS EN 1205-3:2000 Gravity drainage systems inside buildings – Part 3: Roof drainage, layout and calculation. The following results were achieved:
- The baseline flow rate in the gutter without gutter guards was 120 l/m.
- The test with the Gutterflo gutter guard showed no measurable reduction in flow rate.
- The test with a gutter brush product showed a 50% reduction in flow rate – 60l/m
- The test with a downpipe balloon and the gutter loosely filled with leaves showed an 80%reduction in flow rate – 24l/m
- The test with a rigid plastic flat mesh gutter guard showed an 17% reduction in flow rate – 100l/m
1 BS EN 1205-3:2000 Gravity drainage systems inside buildings – Part 3: Roof drainage, layout and calculation.