Mechanical Fixing Of Ridge And Hip Tiles


The new Code of Practice states that "any tensile bond strength of mortar can not be taken into account when determining mechanical resistance". This means that all ridge, hip, valley and verge tiles must be mechanically fixed if mortar-bedded or alternatively use dry-fix systems.

For more details see the sections below.

Why the change?

The use of traditional cement and sand mortars for the fixing of ridges, hips, verges and other roof fittings has a long history in the UK.

This practice is highly dependent on workmanship as the strength of cured mortar is sensitive to many variables. These include cement or sand type, additives, water content, mortar mix composition, temperature, humidity, cleanliness of surfaces, etc.

The new Code of Practice states that mortar alone cannot be used to fix ridges and hips. So, even if mortar is used, the ridges and hips must also be mechanically fixed.

This means if mortar is used then additional materials are needed including a ridge/hip batten with fixings to rafters, a damp proof membrane to protect the ridge/hip batten and mechanical fixings for securing the ridge/hip tiles to the ridge/hip batten.

While the above secures the ridge/hip tiles it does not prevent the risk of mortar failure, resulting in roof leakage and subsequent repair work. A simple way of avoiding all the hassle associated with mortar is to use modern dry-fix ridge/hip solutions instead.

Be Warned:

The NHBC saw claims against its 10 year Buildmark warranty increase to more than £12 million in 2011. Nearly two thirds of all roofing claims against the Buildmark warranty are related to mortar failure.



What to do

All Redland's dry-fix ridge and hip products include mechanical fixings that comply with the new Code of Practice.

Benefits of Redland dry-fix products:

  • Mechanical fixings and all the components you need included
  • Ridge packs provide high level roof space ventilation avoiding the need for ventilation tiles (helps comply with NHBC Technical Standards)
  • Quicker to install than mortar
  • Can be installed even when bad weather is forecast
  • Maintenance free, unlike mortar which periodically requires repointing

Redland dry-fix ridges

In a conventional cold roof construction Redland's dry-fixed ventilated ridge systems, such as DryVent Ridge, DryVent Monoridge or Rapid Vented Ridge, remove the need for low-level roof space ventilation, when installed with Redland's Spirtech 400 2S underlay and a well-sealed ceiling below.

In new build housing situations the elimination of the need for low-level roof space ventilation can help housebuilders overcome thermal bridging issues at the eaves, improving Part L1A SAP ratings.

Redland Uni-Vent Rapid Ridge/Hip

Redland's Uni-Vent Rapid Ridge/Hip is a universal solution for the mechanical fixing of ridge and hip tiles.

  • One cost-efficient 10m pack
  • With a rollable membrane to allow ventilation of the roof space at the ridge or batten space at the hip
  • Includes a universal flexi-seal which is compatible with the majority of ridge and hip tiles.


Uni-Vent Rapid Ridge/Hip Installation (Ridge)

Uni-Vent Rapid Ridge Hip Installation (Hip)

View our other installation videos by clicking here.