This time last year we were called by a client who said ‘HELP, OUR BRICKS ARE LEAKING’!! Visible signs of damp were evident on internal walls, meaning water had come through brick, insulation, block and plasterboard.
So, with winter fast approaching, we’re asking the question - were the bricks really leaking?
Well, no. They were actually doing exactly what they’re built to do. Let us explain...
As the seasonal weather returns (think gale force winds, driving rain and icy conditions) it is natural that this will affect some buildings experiencing saturation and water ingress. This disruption largely occurs due to the velocity of the winds, the direction of the heavy rains and the increased exposure of buildings, due to a lack of natural screening, trees, other buildings for example. To pre-empt the damage this may cause to your pristine brickwork, we’ve compiled a guide of some key considerations to think about.
First and foremost, it’s always advisable to check your local manufacturers website to enquire about the levels of exposure across the country – this is usually denoted as Low, Moderate and Severe. This will ensure the area is suitable to accommodate the build and decide the levels of protection that would be beneficial to you as a preventative method to the extreme weather conditions that typically occur in your region.
It’s worth noting that more traditionally built properties, namely brick and block, possess the weakest mortar joints because the built walls have a small area in which rain can forcefully penetrate into the building’s cavity area. Hence, it’s worth considering that the mortar mix is the correct standard to suit the exposure, as well as the product that it is being used with.
From a clay brick point of view, these bricks have a maximum water absorption, which is tested by each batch produced by manufacturers to acquire a Declaration of Product (DOP) certificate. As part of this rigorous testing process, the percentage of absorption does not become exceeded in these saturated conditions, even if extreme weather conditions persist. If any bricks were to be randomly removed from the outer wall and left in a dry location, they would completely dry within a few hours, which would enable manufacturers and users of the bricks to know that the brick isn’t holding water and isn’t the catalyst of the saturation problem.
Over the past number of years, the insulation of buildings has increased due to improved Codes, with more buildings having full fill cavity insulation in them. The cavity could be 100mm wide, and from ground to roof, and filled completely with chosen insulation to prevent any means of airflow through the cavity and effectively enable natural condensation to disperse. However, in a situation of saturation, the full fill insulation would become wet through in extreme weather conditions and have no means of drying out naturally within the enclosed cavity. The damp can then bloom through into the internal walls of the building. In this case, weep holes, cavity trays, DPC layers within window, door areas are unable to prevent or dissipate the water in these situations.
With Climate Change a more pressing issue than ever, it has never been more important to review industry practices to see if there are ways we can address the issue of building a sustainable future. This is especially true since weather cycles have become more erratic in recent times, causing much harsher winds, rains, warmer temperatures and colder climates. Some of the questions we need to be posing off the back of this are: Should we switch to partial fill cavity insulation? Is it worthwhile for bricks to have air flow through cavities to allow walls to breathe again? If this were to happen, could we then add a thin layer of insulation internally before the plasterboard is in place to maintain protection? Finding these answers will act as a prevention and solution strategy to a pressing issue which needs to be addressed.
Lastly, but by no means least, let’s turn our attention to roofing. Where roofing brickwork meets wall plate/gables, then all methods of flashing need to be built into the brickwork and secured to prevent water ingress. Where stone features are used on gables, these must be positively sealed to prevent water ingress getting into the cavity as these are high up area’s, which can be more exposed to the elements.
So long as the products being used in builds all meet standardised requirements and are regularly tested, they are fit for purpose. However, they are usually dampened (pardon the pun!) for their poor performance simply because, as an industry, we don’t yet understand how our climate is impacting our methods of build. Naturally, this is something that needs further research attention so that building can persist in the most innovative, efficient and sustainable way possible.
For more information on this, or any other building requirement, please get in touch with McGovern on 0191 469 3004.