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Example: Tile & Lead Roof House

Retiled Roof & Dormer Releaded

The existing roof covering was defective and required complete replacement.

• The existing Rosemary clay tiles had reached the end of their lifespan, as evidenced by shaling (splitting and crumbling due to weathering processes such as heat and frost effects.
• The adjoining roof illustrates a number of characteristics which indicate typical roofing problems such as shaling.

Shaling of Tiles

• The shaling is identified by voids appearing under isolated areas of tiling and crumbling from the edges and undersides of tiles.
• As the roof tiles degrade over time weathering will effect an increasing number of tiles and effect the integrity of the roof covering.

Re-Roofing Preparation

• The existing roof coverings are stripped off and disposed of; this includes the Rosemary clay tiles, wooden batons, lead flashings and valleys.
• The flat roof lead dormers previously had not been installed in accordance with Lead Development Agency (LDA) recommendations and have thus have numerous splits are evident indicating they are at the end of their life span and require replacement.

Roof batoning

• Once the existing roof coverings have been disposed of, breathable roofing felt membrane is cut to the relevant sizes and laid into position on the bare roof timbers.
• The felt membrane is then secured as the wooden roof battons are cut to size, laid horizontally in position and mechanically fixed (nailed) to structural roof timbers.
• Re-Batoning of the rafters requires softwood such as pine which has been cut to the dimensions to prevent bounce when driving in the roofing nails.
• Baton boards are secured at each end and at points along their length. battons aren't allowed to cantilever or to be spliced between supports, but are square sawn and butt-jointed at rafter centres.
• Prefabricated roof trusses are generally at 600mm centres. Traditional roof spars (structural timbers) generally at 450mm centres.

Chimney Stack

• The chimney stack is ground out and repointed and lead flashing installed.
• The defective lead flashing is stripped out from the brickwork and replaced with new.
• Lead sheet is cut to shape and the flashing strips are inserted into prepared brickwork joints.
• The top of the flashing is secured - plugged with lead. A lead plug is formed from a roll of lead inserted above the flashing and mechanically fixed to trap both parties together.
• Brick work joints are then sealed with flexible lead sealant to ensure a weatherproof joint.
• As the roof tiling progresses to the base of the chimney stack, a fully welded lead apron is prepared and installed to wrap around the base of the chimney giving 125mm of cover.
• Lead soakers - these are lead sheet cut and formed to sit on top of the tile and also flat against the brickwork - form an up-stand; the chimney stack flashing will then fold down the face of the soaker to give a total weather seal against the abutment.
• The top of each lead soaker is secured by dressing it behind the top of the tile by 75mm.
• Although there are pre-manufactured soakers available for certain ranges of tiles, by using lead we can form soakers to any profile (shape) or size of tile. This is especially useful for older and refurbished roofs.

Roof Valleys

• Roof valleys occur at the point where 2 roof angles join, such as the junction of a dormer window.
• Valley boards are inserted into the correct position on top of the roof timbers.
• Valley boards accommodate the lead which then forms the valley.
• The picture shows the roof membrane secured by the treated batons, the battons are cut to the edge of the valley boards and the membrane is then draped over the edges of the lead. The secondary roof (membrane) is visible in the picture and it provides full weather protection for the house/property whilst construction is in progress.
• The membrane is dressed in the valley to give temporary protection until the lead is fully installed. At the base of the picture is the roll of lead which is fitted in 1.5 meter strips from the bottom and attached at the top.

Hip End Dormer

• The property has a hip end dormer with a pitched central section and flat lead roof sections on either side.
• In its life, temporary repairs to the flat lead roofs have included overlays of felt and brushed on sealants. Because the flat roof lead dormers weren't previously installed in accordance with Lead Development Agency (LDA) recommendations numerous splits indicate that they are at the end of their life span and require replacement.
• The existing lead covering is stripped off to expose the dormer structural timbers, cheeks and brickwork. The existing brickwork is re-rendered as the roof tiling progresses to the dormer cheeks and new lead soakers are fixed. These are later secured beneath turn coated steel clips which provides a full weather seal. The timber cheeks are clad in sheets of lead welted together; these sheets are fixed at the top with copper nails and secured at the base with the turn coated steel clips at 300mm centres.

Dormer Flat Lead Roof

• The flat dormer roof is designed so that water is captured and channeled back towards the roof and drains onto the tiles and into the gutters.
• The defective lead had been painted with a temporary sealant so this is stripped off and disposed of.
• The roofing timbers are checked for rot/structural integrity and replaced if necessary.
• Geo-tech lead under quilt is installed to prevent the lead and timber binding together and preventing expansion of the metal when hot.
• New replacement lead is then fitted incorporating a welded expansion joint or a mop rolled joint.
• Both these procedures allow correctly sized panels of lead to accommodate thermal movement.

New Tiles

• The type of roof tiles Marley Smooth Red Concrete Plain Tiles were specified by the client.
• These were chosen because they are a close substitute to the Rosemary Tiles that were the previous covering.
• Marley Smooth Red Concrete Plain Tiles look very similar to the traditional Rosemary tile, as they provide a small tile effect, however they don't contain the slight, random irregularities which are found in Rosemary tiles.
• The modern alternative also comes with a cross camber affect (horizontal 'bumps') to add visual appeal of a roof.
• The picture of the tile packs show the new Marley Smooth Red Concrete Plain Tiles.
• The nibs that overhang over the wooden battons can be clearly seen, although the cross camber effect is difficult to see.

If you live in Manchester, Cheshire, West Yorkshire or Lancashire, call K-Roofing now on: 0800 1950 350 and discuss your roofing requirements with our experts.