Repointed hip on roof

Ridge Cap Repair and Repointing

Every tiled roof will require maintenance at some point and every homeowner should be aware of the following issues when it comes to periodical maintenance on their tiled roof. The fact is that most homeowners don’t think about repointing or maintenance to their roof until it starts to leak and although this type of roof maintenance can be extremely costly, it can certainly save you in the long run. So what are the most common issues when it comes to roof leaks and the associated repairs?

Ridge Capping and Roof Leaks


At the very peak of your tiled roof, the tiles are usually cut to fit the overall length of the roof, very rarely ending on a full tile and because of this the bond between top tiles and the ridge capping is essential for waterproofing. The ridge capping sits on a bed of cement and is pointed with a flexible pointing compound to seal both the collars (overlapping part) and the edges. If the pointing or bedding cracks, usually at the top whilst still remaining sealed at the bottom, this allows water to pool behind the bedding and eventually find it’s way into the roof space. The majority of mould on the ceiling of homes with roof leaks can be attributed to loose or cracks in the ridge capping.

If you were to look up at your roof and can see the bottom edges of your ridge tiles, loose cement or mould on the edges of your ridge capping, there is a good chance they may require repointing. Generally homes should be repointed anywhere between every 7- 15 years, depending on the type of tile and the previous contractors application. This is a very important part of maintenance and should be done by a professional, to ensure that your home stays leak free during any rain.

Maintenance, Preparation and Repointing


When repairing roof leaks from the ridge line, it is important to change out any broken tiles under or within 3 rows of the ridge capping. This may seem like a no brainer, but I have seen many times when someone has done a rough silicone job that does not create a proper seal. Nothing is better than a new tile for this purpose and considering you have to prepare the surface anyway, it makes sense to cut the ridge capping off and replace the tiles before sealing them again (I know right?).

Preparation is the key to good surface adhesion and a longer lasting lifespan of the product, so pointing over old surfaces will only last as long as the old product does. This means that each ridge cap should be surface grinded along the edges and collars to allow a minimum of 3-5mm of product coverage. Removing any mould, decaying cement (this step may require re-bedding) and high spots by grinding and wire brushing, will ensure that the new pointing lasts the maximum of it’s intended lifespan. The pointing should be trowelled smooth and evenly so that water and dirt can flow away from the ridge capping, preventing mould from be able to grow.

Valley Tray Replacement


The trays under the tiles of your valley cut tiles are another main contributor to roof leaks and because they are metal, are prone to rusting, catching debris under the overlapping tiles and flattened lip edges. A valley tray is a ‘V’ tray with 15mm lip edges on either side that allows water to be channelled down to the gutters and away from the roof. These should be inspected and cleaned out regularly, such as when you clean your gutters. This is very important because water flowing fast down a valley doesn’t need much more than a few leaves or branches to collect under a tile before bridging the edge of the tray lip. This should be done by lifting the cut tiles that sit over the valleys and cleaning out any debris that may be stuck.

The process for changing a valley tray requires cutting the top ridge capping above the valley, removing the ridge caps, all the tiles on both sides and pulling up the trays. The next step is important because it will ensure that the tray is supported adequately and aligned properly on the valley boards. When removing the old trays, I inspect the valley boards for nail heads that are proud and make sure that the bottom section of the boards are supported and meet the gutter relatively flush. It is very common to find the bottom section of the valley boards are lower than the gutter and unsupported for the last 600mm. This is because the last fixing point is the rafters on the brickwork and where the eave section is, the boards are just floating with a angle away from the gutter of sometimes 60mm. This is usually ok because the valley boards can span the distance but will require some packing material to ensure that the tray is supported all the way into the gutter and if not, the tray will buckle and create a leak issue.


Roof Leak Repairs, Inspections and Maintenance


Every year is a good time to inspect your roof for the items mentioned above, whilst cleaning of your gutters and valleys every 3- 6 months depending on your proximity to trees. Most contractors offer free quotes for these items and they can advise you on suitable actions when it comes to valley tray replacements, repointing of the ridge capping and changing out any broken tiles. When it comes to your roof and maintenance, I would suggest that you have this done by someone with experience and knowledge of how any work on the roof can create leaks, when not completed correctly.

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