Is brick the right choice for our extension wall?
Query: My husband and I are planning to renovate and extend the rear of our 19th Century house. Most of the rear wall of the house is faced with brick but this looks somewhat dull and patchy. The remainder of the rear wall is rendered and painted. We like brick as a material and would like the exterior of our extension to look bright and colourful while still respecting the old house. What advice would you give?
Answer: The best way to begin the process of selecting bricks for your new extension would be to investigate the old brickwork on the back of the house. If the historic brickwork looks dull then this is quite probably because it is covered with layers of soot and grime. Old brickwork can be cleaned to reveal its original colour but cleaning needs to be carried out carefully to avoid damaging bricks and washing out pointing or mortar. Your architect can arrange for an experienced contractor to carry out small trials to establish the best cleaning methods before the whole facade is cleaned.
Cleaning and Repointing
When cleaning has been completed it should reveal brighter brick colours but with a gentle patina of age. Cleaning, however, might also reveal the need for some repairs or re-pointing and these should also be undertaken with care. Mortar in 19th Century brickwork is usually lime based (rather than cement based) and materials used in any repairs or repointing need to be compatible with those used in the original design and construction. It is really surprising how careful cleaning and repointing can transform the appearance of old brickwork, especially as pointing can make up perhaps a quarter or more of the visible surface of a brick facade.
How to Choose Your New Bricks
Once the brickwork on the back of the house has been cleaned and repointed it will be easier for you to make an informed decision about the selection of new bricks for your extension. It is difficult to achieve an exact match between new 21st Century clay bricks and weathered 19th Century ones. For this reason, it might be best to start the selection process by looking at brick colours and textures which complement or perhaps even contrast with the colours and textures of the old weathered ones. This approach would aid legibility of the overall architectural composition, that is to say a 21st Century extension to a 19th Century house.
There is a very wide variety of bricks available and good suppliers should be able to show you a range of samples and display panels, including mortar joints. You should not feel limited to those which have a wholly uniform colour as there are many bricks which incorporate a subtle range of colours and tones across their surfaces and such gentle variation can contribute greatly to the visual interest of a building exterior.
Flemish Bond / Stretcher Bond
You should also consider the type of bonding and mortar to be used when deciding about the colour and size of bricks for your extension. In 19th Century Irish buildings, brick was very often laid in a Flemish bond - with alternating stretchers (long sides) and headers (ends) in the same horizontal course. Flemish Bond may well have been used on your house.
Visual continuity between the old house and the extension could perhaps be created by repeating the same bond on the new extension walls, although the brick bond used most commonly on 21st Century Irish buildings would be stretcher bond. This latter bond, typically used with cavity wall construction, is made showing only stretchers and so is arguably less visually interesting than other bonds. A light mortar colour can really enliven a brick facade so if you decide on stretcher bond for the walls of your extension, then the choice of mortar colour will be all the more important to achieve the bright, colourful extension exterior that you desire.
Finally, you mentioned that part of the wall of your house is rendered so you should ensure that all brickwork is protected from spills, splashes or other damage if the render is repaired or decorated.
A good source of information about Irish brickwork is the Government Publications Advice Series Bricks, A Guide to the Repair of Historic Brickwork, also available online at buildingsofireland.ie.
If you are considering changes to your home, work with a registered architect. Check on riai.ie, the registration body for architects in Ireland.
- Architect Mark Costello is a member of the RIAI and can be contacted at firstname.lastname@example.org; strandarchitects.eu
- Do you have a design dilemma? Email your problem to email@example.com.
- Advice is for guidance only and readers are advised to seek professional assistance for any proposed project.