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ADLIan

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  1. ADLIan
    Check with the PUR manufacturers. Generally foil faced boards are mechanically fixed whilst those for bonding have a coated glass tissue facing (normally cream/off white in colour). Remember you will also need a VCL on the deck prior to the the insulation boards and you cannot bond to polythene so fully bonded PUR normally goes onto a fully bonded bituminous felt VCL.
  2. ADLIan
    The grant aided schemes are normally for upgrading existing lofts and are often means tested. Loft conversions come under the Building Regs along with the requirement for insulation at the roof line or flat roof. I assume the thinking is if you can afford a loft conversion then you can afford the insulation to go with it.
  3. ADLIan
    I see this a lot as a planning condition. Typically Planners will require a 'scheme' to be 10% better than Regs based on CO2 emissions and/or fabric energy efficiency and also may dictate it's got to be done by the use of renewables. Distinct lack of consistency even within one planning authority! Self builders and smaller developers have to jump through the hoops but, as ever, the large, national house builders appear to avoid this type of condition, I believe the reason(?) is 'it doesn't make the development economically viable'. Ian
  4. ADLIan
    Rockwool data I have shows cavity batts below DPC starting just above the lean mix cavity fill - I believe this is common to just about all manufacturers and BBA certs
  5. ADLIan
    Beg to differ. You will find just about all built in cavity insulation products are BBA certified for use below DPC
  6. ADLIan
    A ground floor U-value of 0.3 W/m2K would give an automatic fail under the English Regs - must be 0.25 W/m2K or less, area weighted average. 100mm PUR probably gives better than U=0.2 in a typical floor, perhaps closer to U=0.16. This can easily be offset elsewhere in the construction. Note the DER/TER requirement can still be easily met depending upon fuel, heating system - air source heat pump, addition of solar PV etc helping reduce CO2 emissions. High individual U-values will impact on the DFEE/TFEE however and will be more difficult to resolve.
  7. ADLIan
    The nail plate is shown with a conductivity of 17 W/mK - this is the value for stainless steel. For typical nail plate, in galv steel, this should should be 50-60 W/mK. But, as above, probably has little impact on U-value, probably only in 3rd decimal place and probably less than 0.01 W/m2K. Not sure its worth worrying to much about these slight variances in U-values when effect of linear thermal bridges may be your biggest enemy!
  8. ADLIan
    Should also take the opportunity to add/upgrade the insulation. Probably falls under Appr Doc L1B requiring this upgrade.
  9. ADLIan
    The properties to be tested should be chosen by the BCO not the developer/builder - yet to see that happen!
  10. ADLIan
    Another example of lack of enforcement of the Regs! The Building Regs are very specific on the air tightness testing regime, see Section 3.17 of Appr Doc L1A, requiring testing of 3 of each house type or 50% of each house type, whichever is the less. The SAP assessor should pick this up too as a copy of the test certificate needs to be provided for each tested unit and the convention is to add a penalty of +2 to the measured value for the untested dwelling type (Section 2.9).
  11. ADLIan
    Many breather membranes used in TF and roofing are degraded by UV light. Check with manufacturer the maximum exposure, some as little as 3 months, others up to 6 months.
  12. ADLIan
    EPDM upstand at roof edge should be min 150mm high too.
  13. ADLIan
    Sealing the edges alone (must be top, bottom & sides and prevent any air infiltration so cavity stop sock) reduces U-value to 0.2 W/m2K. Not sure how you do this in retrofit. Remember injected insulation must be the fluffy stuff (glass or stone wool, min 18 kg/m3) as this has been shown not to adversely impact the acoustic insulation across the party wall. Do not use eps bead or pur as these may (will?) ruin the acoustic performance and neighbours may complain.
  14. ADLIan
    Work done by Leeds Met Uni and mineral wool manufacturers association. This is one reason party wall thermal bypass was included in the Regs a couple of updates ago. In theory reduces U-value of party wall from 0.5 to zero W/m2K. Check energy savings - payback at above costs may be long time!
  15. ADLIan
    A very good reason not to have injected insulation in new build (perhaps a different case with older houses where anything, even if not fully filled, is better than nothing). Also having been involved in the development of this type of product it is impossible to be sure that the cavity is completely filled and at the right density. At least with a built-in product you can see it installed and check the quality of workmanship. I note some of the volume house builders are using these injected products (allows them to blame someone else for poor installation!).
  16. ADLIan

    EPS Beads

    ADLIan replied to Onoff's topic in Heat Insulation

    Probably not - total lack of any technical info. High performance mineral wool would be best option.
  17. ADLIan
    XPS. OK below dpc.
  18. ADLIan
    As an alternative simply confirm all fittings comply with Table 2.1 in AD G!
  19. ADLIan
    Re linear thermal bridges. The difference between the default y-value (0.15) and the calculated value from a more detailed analysis using ACDs may only about 3 SAP points. However it will make a massive difference in CO2 emissions (DER) and the fabric energy efficiency (DFEE). Probably enough to result in an overall Building Reg failure on these 2 criteria.
  20. ADLIan
    Bringing this back to the top in the absence of further information. The original assessor is correct, the Sunamp adds nothing to the electric heating and it is treated as an instantaneous space & water heater, no thermal store is accounted for. The fact that the house is all electric will account for the relatively low EPC rating even if very well insulated, the PV helping the rating though.
  21. ADLIan
    Got to agree. More useful if public to be any use for the OP. Noticed this was discussed on here a couple of years ago with no real resolution.
  22. ADLIan
    @vivienz have you discussed this with your SAP assessor? Could be that he is treating the sunamp correctly within SAP. An all electric house will prove difficult to get a pass, due to the high CO2 emissions, unless PV used. Perhaps someone from sunamp ( @AndyT ) will be along soon to advise. Also all linear thermal bridges should be noted and assessed so this listing should be there and is important.
  23. ADLIan
    Note that SAP 'approved' product must be used if you want to take advantage of this technology. Also don't expect any meaningful improvement in SAP rating (+1 point if lucky?) or CO2 emissions (less than 0.5 kg CO2/m2/yr reduction?) depending upon system, water use etc, etc.
  24. ADLIan
    There are 2 basic types of joist hanger - onto masonry and onto a timber ledger. The masonry ones are built into the mortar beds and hook over the block - they are not nailed. The others are nailed onto the timber ledger. In both instances manufacturers give very strict fixing instructions.
  25. ADLIan
    I’m an accredited assessor. PM if you need more info.
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