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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.

Buy individually or both books together. Delivery is free!

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    Apologies for the rambling opening post, I've been lurking for a long time and all the issues seem inter-linked in some way.

    Our roof has no soffits, the rafters rest on the outer leaf of the cavity wall and protrude direct to the outside. The joists are attached to the rafters directly on top of the wall. Presumably this is not good in terms of the joists being a thermal bridge to bring the cold into the ceiling space (or let the heat flow out, depending on how you see it). The current insulation is only the depth of the joists (4 inches?), and the joists are all boarded over. The felt (presumably from the early 1950s when the house was built) is now falling off the rafters.

    There is a more recent extension, which is superficially OK, but the plasterboard was dot-and-dab, not all of the suspended floor was insulated underneath, and the bathroom and en-suite ventilation is through ceiling-mounted fans which push the moist air through the loft (under insulation).....and because there's no soffit they vent into the cavity wall between some rafters. In fact, they vent to just above a window, and we now understand why that window has always seemed to suffer from damp patches in the upper corners.

    To tackle the extension, I think we need to:
    i) get under the floor and stick some insulation in. This could be tricky as I think the void is only around 12 inches.
    ii) punch holes in the plasterboard and fill with expanding foam.
    iii) make sure the plasterboard at the top of the walls is sealed to prevent air flow.
    iv) put external vents through the masonry for the bathroom extractors (it's a gable-end loft, so comparatively simple).

    I also need to tackle the rotting felt and thin insulation. I suspect the only answer for the felt is to lift the roof tiles and put a newer membrane on - a job which would be much easier were it not for the solar panels. For the insulation, would I be crazy to leave the boarding and simply add another 6-9 inches of insulation on top?

    If anyone has any wisdom before we embark on all this, I'd be glad to hear it!

    Of additional note is that the gutters hang from the rafters, but they sag and spill over the top when it rains. This overflow then either splashes against the pebbledash (which is coming off in places where it has got too wet), or blows against the house walls. Incidentally, only our half of the semi is pebbledashed (the extension and the original nearly match in colour), but the other half of the semi is brick. I only mention this because my day-dreaming has made me think of changing the roof pitch, introducing soffits, wrapping some EWI around, and generally making things better. I don't think we can actually do much about the roof pitch, or soffits, and the gable end only has a 5-10mm overhang meaning EWI is awkward.

    I feel we "ought" to start with the roof and bathroom ventilation and work down through the house, but as I said before, your wisdom would be welcomed.
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