DPC and DPC detail for extensions this is how our inspector likes us to do this detail, other inspectors/sites might vary thought this would be a helpful video though
Great video. We have radon here as you say every area is different. OUR DPM goes straight through the cavity two courses lower that dpc on the external skin which forms a complete seal between floor and cavity. Dpc is then the usual 4 inch and we add weep holes so any water dont sit on the tray . Every area is different great detailed video. Justin brickright 👍
Aah that's interesting how your DPM is. Even in Derbyshire I've found different inspectors like different things..just depends like you say buddy! Glad you liked this little video, thought it might be helpful for some people who dont often see the dpm in. Hope your not getting too wet today buddy!😂😄
@@IzzytheBricky Off on hols at mo in the rain typical UK mate .Interesting how different areas different practices. Most bricklayers like to build brick then block for obvious reasons bug here in wales we always use celotex in the cavities so always block first harder to out your brickwork but i think celotex with a clear 50mm free cavity is better than cavities filled with batts . Anyway great insight to our world great videos keep em coming Justin 👍
Please do more educational videos please bro 🙏🏽 also love your videos, really helps for a youngen loke me who has jusy finished there NVQ Level 2 in Bricklaying
I remember 10 odd years back having to play origami with the red radon barrier, it was a nightmare to stick (with said radon tape) then a couple of yrs later they decided radon was not in area so we didn't have to use it any longer lol , I lke the way building regs change every year but modern houses are still shit , small the only thing better is insulation, altho new regs this yr on about keeping them cool in summer lol , old ones built with no regs seem to last longer ,look nicer too.
Seen people do this before and had to go back to remove it as water can be carried inside due to bridging the cavity at dpc level. If it was lower then fair enough but anything at dpc level or above bridging the cavity is a recipe for disaster.
I think you’ll find that if water tracks through the DPC something else has gone wrong or isn’t correct. If the exterior ground level is correctly installed 150mm below DPC as stated in Approved Document C of the building regulations then no water will be able to track across. Izzy is correct in saying the radon barrier bridges the cavity as this is a standard radon detail however, the radon barrier should be continuous or at minimum lapped by 300mm and taped with radon tape. Ben
We have 1 dpm sat on top of our hard-core and sand blinding that thr concrete goes on and it flies over both internal and external skins to form a radon tight barrier. Then we have a 4 inch dpc and a 18 dpc tray straight on at first course with weep holes.
Izzy do you tape your dpcs together on the bed joint or just leave lapped 🤔 seen loads of different ways of doin it just wondered your preferred method, seen lads running silicone ct1 all on the bed to seal the two together and seen others just thin bed with gear and other use the good old vis queen tape lol good video mate 👍 new sub 😊
Ayup mate! Thanks for subscribing fella! We tape the DPC to the DPM. The dpc usually has a good 300mm overlap on the dpm and then its taped :) to be fair..anyway is pretty good👌😁 Hope your having a good weekend fella🍻🍻
As a building inspector may I just add that you’re correct to lap any joints by 300mm however, you should also tape this with a radon tape. Essentially it works like double sided tape but the critical thing is it forms a gas barrier preventing any gas penetration into the property. Ben
@@BerkleyBuilds yes I understand that., but when using the tape to tape dpc tray to radon barrier and the tape runs all the way along the bed joint (of the outside skin) is this acceptable as in theory your walling on top of a squishy tape
@@kingofthetrowel1725 you don’t need to tape the DPC tray to the radon barrier because the radon barrier has already formed the gas seal. You’ll have 3 layers of plastic, first layer is your 1200g DPM to form the radon barrier that comes over the sand blinding up the block and over the cavity, second layer will be your cavity tray and third is your 4 inch DPC. You only need to lap and tape joints in the first layer if one sheet is too small, where possible limit joins. Hope that answers your question.
There are TWO...TWO DPCs. Number ONE. Raydon Barrier. This is the DPC you keep referring to "bridging the cavity" is the RB. This is bedded on both the external brick and internal blockwork at the same FFL hight...So, in one respect, your quite right to raise concerns about bridging the cavity and the other comments you made. These comments would be totally true if I were to only have this one DPC detail in. HOWEVER. Number TWO The 2nd DPC; is sitting on top of the first Dpc (overlapping it) on the external Brickwork and then..goes 225m up onto the first block laid ABOVE FFL. Therefore. The first DPC which is "bridging the Cavity" is totally irrelevant in reference to damp and moisture. As the SECOND DPC is doing all the work and protecting the building from penitential Damp and raising damp. How can moisture cross the cavity when moisture cannot even get into the tray detai created, as the 2nd DPC overlaps the first? Regardless of the detail, I've yet to have an issue, or even have any concerns raised by the multitude of inspectors used over the years, nor NHBC when working on multiple sites. A thing I like to remind myself if that houses use to be built without all these DPCs and precautions all the time. As you well know. They rarely have any issues with damp and moisture. Cheers fella
Been doing this last 10 years on sites and on all privates. Never had an issue or been told to do it any other way by all of the inspectors over the years. That Dpc goes on top of the fist internal block and then down and out 3 course
Also the first Dpc bridging the cavity is a Radon barrier.☺️ just the way we've been told to do it mate. As I said, all over the country inspectors want or expect different Dpc details, as you probably know☺️👍 Hope your well mate
