Hello again All,
Now I have the information I need to fit my door frame my next question is which course up from DPC do I start to lay my cavity wall ties? If I start on the first course up from DPC I will need to lay one course of common bricks on the inner leaf so the wall ties will line up with the third course of bricks on the outer leaf, so perhaps I need to start laying wall ties on the third course of brick (which will then line up with the first course of block) up from DPC. This seems too hight up from DPC but I don't know and I'm just concerned that I don't want to get started laying bricks & blocks and then find that I should have started a course of so lower down, plus if I laye a course of common bricks on the inner leaf these will be seen on the inside of the building (workshop).
I ow have another problem in that I must install a special blue visqueen methane gas barrier under the floor concrete which must come up the sides of the inner leaf and also continuously lap over to the outer leaf which means I will need a cavity tray all round the building with weep holes etc. Where should I start to lay wall ies now? I will be using block on the inner leaf and I presume I must install the cavity tray from the DPC on the outrer leaf up to the top of the first course of block (3rd course of brick). Will ties interfere with the cavity tray (puncture etc.) so should I start laying ties above the cavity tray?
the visqueen is to be laid before the concrete slab is laid.
It should be explained on the plans.The inner leaf of blockwork should be
built to dpc height.The outer leaf must be left 1 course of block down so
the visqueen when laid runs down the outside of the inner leaf and crosses
the cavity to the outside edge of the outer leaf.
Its supposed to stop raydon gas from entering the property,dont ask
bloody supid ideas,even the the building inspectors dont understand it
but its building regs so you have to comply.
Okay many thanks indeed for this. I also don't understand this or even why it has t be fitted because the property along with all the other properties in the terrace have cellars so if there is any gas below the ground then surely the cellars will be full???
The gas resistance visqueen is also much more expensive than standard visqueen and there is all sorts of special blue gas-proof tapes and silver jointing tapes that cost the earth. I feel like I'm going to be laying concrete over Â£500 of unnecessary materials.
Have a word with building control I have used a high grade visqueen
before whitch was cheaper,but you have to check first,It depends on
different local authoritys , they have their own way of doing things.
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