Carrerahill

Hi guys, I am converting a sun-room into a kitchen, I am currently waiting on planning and warrant. To put you in the picture the existing sunroom is constructed of a cavity wall to about 600mm AFFL but externally about 1500mm above ground level, so the wall is actually about a 2000mm wall from the foundations, it has a 100mm cavity and is built in 100mm concrete block - see photo attached, I removed some PB to do an inspection. The top of this wall is then closed, and UPVC windows are fitted around 3 walls. The proposal is to convert it into a proper room which the kitchen shall move out to. So the questions begin! I had a look through the building warrant drawing and this is what it says: Cavity wall construction consisting of 19mm render on 100mm block with 50mm clear cavity and 145mm internal timber frame construction consisting of Tyvek Reflex insulating breather membrane to BS 4016 on 10mm plywood sheathing on 47 x 145mm SC4 pressure impregnated timber studs at 600mm centres. Walls finished internally with 12.5mm Foiled Back plasterboard on 70mm insulation on perimeter walls internal areas as standard plasterboard and 12.5mm moisture resistant plasterboard to en-suites, bathrooms and utility room, all joints taped and filled. 140mm thick Celotex XR4000 or equal fixed between timber studs with Visqueen vapor barrier stapled to internal face of studs in Bathrooms. Within 125mm studs allowance of 25mm given to run services within timber framing. This is clearly my architects standard paragraph, but to adhere to it as closely as possible my thinking is that I shall need to sit a 145mm sole plate on the top of the inner concrete block, but what about the 45mm difference, the construction method above says a 50mm clear cavity, so my thought is that if acceptable I can allow the timber to overhang 45mm into the cavity, but with 10mm ply (local merchant does 9mm or 12mm ply and OSB... so I was going to use 9) but that then means the clear cavity is only 46mm - I suspect I may get away with this or do I need to overlap the frame 5/6mm into the inside of the room. Anyway, I am sort of thinking aloud there, what is acceptable - 145mm frame on a 100mm block wall? The next thing I note is it says, "Walls finished internally with 12.5mm Foiled Back plasterboard on 70mm insulation on perimeter walls" so does that mean that between the studs in my extension I need to put 70mm (seems a bit thin by today's standards) insulation, then attach foil-backed PB to the studs - job done wall built. But I then read the sentence about the 140mm Celotex as saying I need to put 140mm insulation between the studs and a Visqueen VB if a bathroom, OR does the whole sentence apply only to bathrooms? Badly written sentence frankly, 2 interpretations for sure. If it does only apply to bathrooms it should say, " Within bathrooms 140mm thick Celotex XR4000...". What are your thoughts here? Thanks

Hi all, just joined the forum as I am about to build an extension and thought being a member of this forum would be helpful in helping me through with some of the questions I am going to no doubt have. A little about me, I am a consultant engineer, my discipline is electrical but I am always closely involved with the mechanical and structures and architects so after many years of looking at drawings and visiting building sites you can get an idea of things that are not your area which is helpful. My interests and hobbies include running, walking, all things DIY; from woodwork to automotive repairs. When I have finished our house renovation and build I am not sure what will replace that! I do almost all my own work and hate bodging. We moved into our current 1960's semi 2 years ago and so far we have totally renovated upstairs (except the bathroom but there is a reason connected to the extension), this included things like properly bricking up, venting and capping the fireplace in the master, rewiring small power and lighting circuits with new centralised lighting control which can be tied into a BMS system eventually, running in RF/data/phone etc to all rooms, over-boarding ceilings, plastering and fitting plaster cornices, shaker panelling to the master wall in the master bedroom, walls plastered where needed including the whole ground and 1st hall, all new skirting/window surrounds and architraves, removed the solid balustrade to the stairs and opened it all up, removed the wall to the under-stair cupboard and fitted 2 large drawers and a single cupboard. The living room was gutted and had a wood stove installed, I also built out the chimney breast on either side with plasterboard shelves, again over-boarded the ceiling, plastered, fitted plaster cornice and laid Ted Todd flooring throughout the ground floor. I also rebuilt a column to the front of the drive, someone had opened the wall up a bit to make way for modern sized vehicles, but they had just left the end of the wall cut with no column to match the opposite side. Oh and we had the guttering and soffit and fascia boards replaced to the front of the house. So far the trades I have used are stove man who is also the roofing/gutter man and my plasterers. I am about to build an extension which the kitchen shall move out into and a new garage. On the extension I am able to cheat a bit as I am already out of the ground because there is a large sun room which we will dismantle and build up from. Planning application is in for both garage and ext. and application for building warrant is in for the extension - they have been in about 2 weeks now so hopefully we will have something in about 4 weeks according to my architect. I was studying the warrant drawings and have started to QS the project to get an idea of cost but also to start understanding what I am going to have to build so the questions are building up. I shall start posting; hopefully in the correct sections, my questions on bits and pieces I want to start bottoming out.