Mullions are vertical stones between windows.

Delaminating mullion. Replacement stone mullion required.

Mullions are the vertical stones between windows. They help support the lintels above. Like other stones, they should have been laid with the layers of stone running horizontally. Such long stones were hard to obtain, so the mullions were often laid with the stone layers running vertically. This means they often weather away (delaminate).

Problems can also occur at the base of the mullion, with additional wear from splashes from the cill.

Repair as for other stone defects.

If the stone mullion is very badly worn, it should be replaced with a new stone mullion. Precast concrete mullions are currently not recommended and would not be permissible in listed buildings or conservation areas.

Professional help recommended?

Although the work may appear straightforward, ensure your builder or tradespeople have the skills for the job. If in any doubt, get professional help to specify and organise the repair.

Who pays?

These are part of the structure and normally a common repair.

406 305 Under One Roof

Ask for help from our team of tenement experts

Managing and maintaining a tenement building can be difficult. Under One Roof offers a free enquiry service that allows you to ask specific questions relating to your building.

Ask an expert
Newsletter
Privacy policy
Terms of service

Mid ceiling

Below ground level

Your tenement may have a basement, sometimes used for living accommodation or sometimes used for storage, cellars or wash-houses. These buildings will often also have a 'dunny' between the basement…

905 800 Under One Roof

Energy efficiency improvements

Adding insulation and draught-proofing can save money and the planet but in…

2560 1707 Under One Roof

Insulating traditional solid walls

Recent research suggests that traditional solid stone or brick walls provide better…

2560 1707 Under One Roof

Flat roofs

Flat roofs can be found on buildings of all ages. They can…

406 305 Under One Roof

Asphalt flat roofs

On stone tenements, asphalt roofs are found on: 'high backs' - raised backcourt…

406 305 Under One Roof
Start typing
Privacy Preferences

When you visit our website, it may store information through your browser from specific services, usually in the form of cookies. Here you can change your Privacy preferences. It is worth noting that blocking some types of cookies may impact your experience on our website and the services we are able to offer.

Our website uses cookies, mainly from 3rd party services. Define your Privacy Preferences and/or agree to our use of cookies.