WWilts

What tape for plasterboard joints? Assuming skim finish

Or in somebody else's? Trying to give sparky ideas that might depart a bit from the same old same old. Airtightness is one consideration (2 storey new build with cold attic), but also How lighting can make life better New tricks with new toys welcome if not huge cost difference from same old same old.

Budget option that works: Tyvek Housewrap. Airtight, vapour permeable.

Passiv Haus airtightness guide recommends a) airtightness paint to seal such areas or b) parge coat

BR drawings & spec notes found very useful for agreement on price, for reassuring the BCO, for the builder to follow precisely, for agreeing on what is a variation etc In our case the BR drawings sufficed, sometimes supplemented by details we provided to improve energy performance

Yes. But instead of the vertical bit sitting against the block surface, it will sit against the perpend mortar. Is that sufficient?

Timber first floor, cavity wall blocks inner leaf, brick or stone outer leaf. Question re lateral restraint straps. Currently lateral restraint straps are being inserted through 1:5 cement:sand mortar perpends, with little or no anchoring to the 7N aircrete blocks of the inner leaf. Will the mortar alone be strong enough to serve the purpose of the straps? Some 1:6 mortar is said to have 7N/mm2 compressive strength at 28 days. Still, seems a bit dicey. To insist or not insist, on anchoring the straps to blocks. That is the question.

Tks, useful info. Trying to understand how to put it into practice. Options appear to be a. Airtightness tape instead of ordinary tape b. an actual airtight membrane over the join, taped down c. Wet plaster just over the join

Plasterboard to receive mist coats and paint. Question re joins between adjacent boards: Will ordinary tape and something like Gyproc Easifill suffice to do 2 things a) allow decoration-ready surface for mist coat b) reduce to negligible levels any air leakage through the joins

Have I understood correctly? option 1 No plasterboard, plaster on to blocks. Good airtightness option 2 Plasterboard on adhesive strips (sealed especially top and bottom). Airtight only if taped at plasterboard junctions, OR possibly if scrim+skim applied over plasterboard. Other consideration is decoration. Can plasterboard with adhesive strips be painted without a skim on top? Has budget implications.

Yes. It is the junctions between plasterboard units that is of concern, in addition to the above. To use airtightness tape or not. Scrim & skim presumably can go over airtightness tape.

Yes

Builder believes it is. We think that in addition to scrim+skim, airtightness tape necessary for plasterboard junctions. What will suffice? Tight budget. Not aiming for Passiv Haus, just what is achievable on a budget.

Any harm using just plain polythene around the joist ends and at the perimeter of the first floor void? The timber joists will breathe into the internal air space (room air). Looking for budget options.

Very well so far. Detailed tender definitely helps, and the going rates for labour help too. Extras can be identified and an agreement at the outset to put out major extras to tender helps. Promised a good bonus to builder if the build is completed within budget. Also had agreement for 50% share in price increases or savings. But just the incentive and a collaborative approach seem to work well, not enforcing the 50% clause so far. Also managed to get agreement for some major materials to be purchased by us. Can save thousands that way. Cutting out unhelpful frills helps the builder to meet target and improve the chances of receiving a good bonus at the end.

No door. Just an opening in the cavity wall. At this height it is an internal wall. Above the porch roof it turns into an external wall. Question is whether the Catnic lintel (cavity) can rest on not padstone but facing concrete brick (or 7.3N aircrete block). Ample bearing, over 200mm.

A little over 1 m

External wall cast stone blocks (2 storeys minus 2.1m tall opening under lintel) plus roof trusses above that. Cambrian slate roof covering (20kg/sqm)

Builder has put in ordinary concrete facing brick instead of padstone

Can a Catnic cavity wall lintel rest on ordinary concrete brick rather than padstone? Or even directly on 7.3N aircrete block without padstone? Context: 2 storey external wall with an opening at ground floor level.

Koemmerling windows, PVCu How to fix plasterboard securely to the frame? (A in pic) Is there an industrial grade airtight adhesive?

Thinking of VCL on inner face of inner leaf blocks, held to wall by battens. Then plasterboard fixed to battens, skim. Would 500 gauge VCL suffice? And are there serious disadvantages to this approach?

55 dB is the claimed performance. Google searches suggest low frequencies are the main challenge. Family members concerned about boiler noise going upstairs. Any recommendations for 21kW boiler that is relatively silent?

Yes

How to stop ground floor boiler noise going upstairs to bedrooms or through wall to kitchen? Yet to be installed. Probable location: in a utility cupboard about 1000mm square, with blocks on 3 sides (incl external wall) & cupboard doors at foot of stairs. All this is still being built (1m high from floor level so far) Options considered so far: Acoustic box with mass loaded vinyl (around boiler only) Fibreglass curtains across the doorway of the utility cupboard (washing machine & tumble dryer will live there too) Soundproof doors Parge coat of 3 walls Others? One obvious solution that works? PS Boiler dimensions about 700 mm x 350 x 400 Noise level about 55dB. Presumably lots of low frequency noise.