Concrete Gutter Removal in Chester
On the 3rd of May we were commissioned by Mr. Ben Johnson to remove his concrete gutters and replace them with a structural backing board, 25mm of PIR insulation capped off with PVCue fascias and soffits, and Kay Flo rainwater system.
On the 12th May 2014 we commenced work on the semi detached property in the Chester area. We arrived on site at 8:00 am, eager to be present to ensure that the scaffolding was erected correctly. The scaffolding company (Twin Towers from Warrington) erected towers to front and rear elevations, joined with handrails and toe boards to form a stable working platform. A 6m Youngerman board was used to span over the rear conservatory. The scaffold was erected with a deck height, just 400mm beneath the concrete gutter soffit.
The scaffolding deck and conservatory were covered with a protective tarpaulin to minimise dust and debris prior to cutting off the existing concrete gutters.
The concrete gutters were a two part type consisting of a square profile concrete gutter and lintol tray, with a sit on lip bedded on mortar to the external gutter upstand.
The particular problems with this type of gutter are:
1) The thickness at the wall abutment is 200mm, and requires a minimum of 16” circular diamond blade diameter to cut the concrete gutter blocks flush with the wall. This leaves a 25mm uncut portion to the underside, so we used a tungsten carbide offset plunge cutting brick blade to cut the last 25mm of the relatively soft concrete.
2) At the point of cut the existing concrete gutter profile upstand between the gutter and lintol tray is only 30mm thick, thus the lintol tray had to be filled with cast insitu concrete throughout its entire length, to ensure a good fixing (minimum 40mm) is achieved by the frame fastenings and to ensure that the remaining concrete gutter does not fracture during installation of the backboard.
During the installation process the existing sarking felt to the first row of tiles was replaced. The rear elevation second row of felt was also perished and was replaced at an additional cost of £250, using a Protec breathable roofing membrane.
The project was hampered by delays on the motorway on day two due to a wagon carrying chickens overturning, releasing 6000 chickens onto the carriageway! Our journey from Preston to Chester took just over 4 hrs and with the extra work replacing the second row of felt, the project took an extra day to complete, 3 full days in total.
The adjoining property had previously been subject to a similar scheme, however we noted several defects. They hadn’t provided a structural backboard or an insulation layer. Instead they had screwed offcut lengths of plastic profile to the remaining concrete, and then fastened the fascias to the plastic profiles. This resulted in a final installation thickness of only 44mm. Our installation thickness was 80mm thus we had to use corner joints to finish the abutting joints to the neighbouring property.
No joint had been made between the adjoining gutters on the previous concrete gutter installation providing each property with its own independent system. We decided that we would retain this arrangement, particularly as each property had sufficient outlets to adequately discharge the rain water from the roof.
The project was completed within the 3 day allotted time span and the property owner, Mr Johnson was more than satisfied with the completed installation.