I am building a workshop extension and I am almost up to DPC level and ready to fill the cavity with lean mix concrete to ground level but a friend told me that I should have installed a Cavity Tray below the DPC with weep holes to drain any water from the cavity. There is nothing on the plans that mention this but I need to install a methane gas barrier and the installation notes for this do show the membrane being fitted to the inner leaf at DPC level with a cavity tray down to the outer leaf to just above ground level so I'm now worried that I may have to demolish several courses to fit the cavity tray and weep holes.
PROBABLY NOT WHAT YOU WANT TO HEAR BUT AS BUILDING INSPECTOR WILL WANT TO SEE THE FOUNDATION TO DPC CONSTRUCTION BEFORE YOU CAN PROCEED WITH BUILD, YOU'LL HAVE TO BITE THE BULLET AND DEMOLISH THE OUTER SKIN TO THE LEVEL REQUIRED TO INSTALL THE CAVITY TRAY AND WEEP HOLES THROUGH MORTAR JOINTS IN RECONSTRUCTED BRICKWORK BACK TO DPC LEVEL.
Many thanks for this reply. It may not be too bad as I've not gone too far up yet but I'm not sure what level the weep holes need to be fitted. Are they to be fitted in the perps at the side of the bricks level with the lean mix cavity concrete or do they go higher up towards DPC level. I was going to set the DPC level at the second course above ground level.
Last year 64% of the questions asked in our forum were answered within our DIY project pages at www.diydoctor.org.uk/projects.htm The project pages are now separated alphabetically and your answers are accompanied by diagrams and the ability to see, and buy, the tools and/or required to complete your project. Use our search box to look for your answer and save a great deal of time and money!
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!