RIBA Core Curriculum
- Building conservation and heritage
- Design, construction and technology
- General Awareness
The history of English architecture is intertwined with the use of clay tiles with varying periods of popularity. This CPD looks at the roots of traditional heritage roofing and then moves forward to consider the modern challenges associated with heritage roofing and product selection. The course then highlights how designers can recognise potential issues and minimise the risk of damage associated with heritage roofing.
In this section
- Good roofing practice
Good roofing practice
Roofing needs to be carried out in accordance with BS5534 Code of Practice for Slating & Tiling and BS8000 Part 6 Code of Practice for workmanship on building sites for roof slate, tile coverings and cladding.
A very important aspect of roofing is that of ventilation and the eradication of condensation problems. This is a complex subject which could form the basis of several lectures on its own.
To eliminate condensation in all roofs, you should follow the Building Regulations Part F2 and BS5250 2002 (amended 2005).
Duo pitched, lean to and mono pitched roofs (insulation at joist level) – Cold Roofs
These require 10,000mm² per metre of ventilation at the eaves or low level plus 5,000mm² per metre at the ridge or high level.
Duo pitched, lean to and mono pitched roofs (insulation at rafter level) – Warm Roofs
These require 25,000mm² per metre of ventilation at the eaves or low level plus 5,000mm² per metre at the ridge or high level
All ventilation components must be designed to prevent the ingress of rain, snow, birds and large insects. The minimum gap size must not be less then 4mm to avoid excessive airflow resistance.
With the advent of In-line ventilation systems the days of ugly pipes protruding through the roof are over. A feature of these ventilation systems is that they are designed to vent through the product, which is made to fit in the same line as the standard product.
In-line Ridge Vent, Plain Tile Vent and Eaves Packs all comply with building regulations but do so without being obtrusive.
Keymer are members of the Surevent campaign for the best practice in the ventilation of cold roofs which deals with the contentious issue of vapour permeable underlay as the only form of ventilation.
We also now provide a Dry Fix Ventilation system which vents at the Ridge or Hip and also allows the fittings to be dry fixed in accordance with NHBC requirements.
For more information please see the Control of Roofspace Condensation CPD.
Great importance is placed upon specification of materials when detailing the plans of a new project. Why go through all this effort when so many the plans are subsequently altered to low priced and sometimes inferior products.
To quote John Fidler, former Head of Architectural Conservation at English Heritage:
“In English Heritage’s opinion the character and appearance of towns and villages across the country are being diluted: by a lack of attention to material details, by the absence of appreciation for the underlying and vernacular appearance of the local environment and by a fixation on roofing work with initial costs not a true value-for-money assessment of cost-in-use.
There is a need to revitalise the clay roof tile industry before all the important local character of our towns and villages is lost from sight under unsuitable substitutes and foreign imports of inappropriate appearance. As a nation we must surely place a very high value on protecting the genuine article – the real thing…”.
With the drastic reduction in house prices suffered in the late 80’s and early 90’s, attention was focused on reducing costs of new build and refurbishment. Local planners were put under severer pressure to substitute cheaper materials.
It is important that at all stages of the design and build process that the original specification is adhered to through to completion. In the case of clay tiles this not only involves the architect, planners and quantity surveyor but also the main contractors, the roofing contractor/merchant and the tile.
At the end of the day a substitute tiles is just that a substitute and not the specified product. It is everybody’s challenge for us all to commit ourselves to “Preserving the Nation’s Roofscapes”.
Red Tiles from our Shire range of hand made tiles were used on this modern dwelling, short listed in the Clay Roofing Awards.
The National Trust’s Grade II listed pub built in 1540 in south east London. The local for William Shakespeare and Geoffrey Chaucer, it is situated in the shadow of London Bridge. Re-roofing required 60,000 hand made clay tiles and architects Peregrine Bryant specified a mix comprising Red, Elizabethan and Antique.
You’ve reached the end of the CPD. To make sure you’ve taken on board the key learnings of this course, please fill out the quick multiple choice Q&A below. This will certify that you have completed the CPD and provide you with an email certificate, which, if the course is accredited, you can share with RIBA.