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Viewing 11 posts - 1 through 11 (of 11 total)
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  • October 9, 2014 at 6:10 am #1955
    philgregg
    Participant

    Hi All. I recently visited a newly built home, approx 12mths old, built under a community housing scheme. The occupier was beside herself that the home was extremely damp ( water running down windows and walls) and her families (1 Adult and 4 children)health was deteriorating quite badly since being in this home.
    I have enclosed a picture of the home to give you a perspective. The house is in a gully close to a stream, there doesn’t seem to be any signs of pooling water, the underfloor is insulated with Polystyrene, no damp proof on the ground, single glazed windows and no roof cavity. The kitchen and bathroom have extraction fans, how well they work may be questionable. Other than putting damp proof on the ground I am not sure what else to suggest… We can’t use a ventilation system as there is no cavity. The moisture level in the house is very high. Does anyone have any ideas on what we can do to stop the moisture.

    October 9, 2014 at 9:35 am #1956
    Norman Smith
    Participant

    Hi Phil,

    Damp proofing polythene on the ground seems a no brainer, but is there currently sufficient air flow across the ground through sub floor ventilation grilles or whatever to remove the rising damp? Dig a screwdriver 50mm into the ground to get a true picture of the state of the sub-soil. It is possible the house started life very damp (i.e. built with wet timber) and its still drying out.

    How aware are the occupants of the many modest steps to minimuise moisture generation and then remove it through natural ventilation? e.g. security stays on windows so they can kept open so bedrooms can be ventilated at night, thus removing the XX? litres of water vapour we each generate when sleeping.

    Probably no silver bullet but a number of measures/actions required.
    Cheers, Norman

    October 9, 2014 at 4:05 pm #1957
    alexking
    Participant

    Also check for signs of roof or wall leaks (I would hope this won’t be a problem for a new house, and also difficult to detect with no roof cavity) Also check plumbing problems – leaking supply or shower discharging directly on the soil etc. With moisture problems (after the house has dried out any moisture from construction) there has to be a source; either rising damp, faulty structure (moisture from outside) or an internal source. Do they dry clothes indoors? Is the dryer vented? Are they ventilating? People used to an old drafty house may need to change their habits for a more airtight home.

    Try to identify (or rule out) possible sources, before you can offer a solution.

    October 10, 2014 at 6:21 am #1958
    Fred Braxton
    Participant

    All good. I’d put money on rising damp, so suggest DPM on ground. Also, if there are heaps of downlights that could exacerbate the problem

    October 10, 2014 at 9:43 am #1959
    Phil Squire
    Participant

    Also if they are in the bottom of a gully beside a stream, Relative Humidity will be quite high, so once the house cools off at night condensation will be likely on cooler surfaces. Same practices apply however, which is heating, insulation, ventilation, and limiting of internal sources of moisture.

    Does anyone have any experience of high humidity climates – especially cool ones?

    October 11, 2014 at 6:35 pm #1960
    Norman Smith
    Participant

    Understanding the cause is not to identify the solution but two possibly relevant components from what we know so far, which have been alluded to;

    1. If the house was built under a community house scheme then coordination of construction and possibly some volunteer labour may means there is a fault re drainage or building,

    2. Its reasonable to assume the section is not prime land so there could be systemic issues with regard to e.g. water tables or run-off.

    Norman

    October 13, 2014 at 8:47 am #1962
    philgregg
    Participant

    Thank you all for your thoughts, a number of areas I can go back and investigate. Shame there is no silver bullet.

    October 14, 2014 at 4:16 pm #1967
    Gleb Speranski
    Participant

    Hi Phil,

    If you still require a further advise can you please let me know if the house is heated. Also what type of floor is in the house?
    I can’t find the photo you’ve uploaded- where is it please?

    Regards,
    Gleb

    October 15, 2014 at 9:33 am #1968
    philgregg
    Participant

    Hi Gleb

    Thanks for advising that photos didn’t upload, I have resized and attached.

    Yes the house has insulation, Batts and expol under floor. I suggest the expol under floor was used to get the thermal rating up and then not have to have double glazing.

    Heating downstairs is with a Fujitsu heat pump 4.8kW. Sizing is ok for lounge etc. Probably should have been a 6 to 7 kW to allow drift up stairs for the bedroom.

    Total house size is 90m2 built 2012

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    October 15, 2014 at 1:44 pm #1971
    Gleb Speranski
    Participant

    Hi Phil,

    Thanks for the photos. They are astonishing.
    Here is my assessment of what is going on and recommendations:
    1. The fact that the house is at the bottom of a hill suggests that there can be a very substantial moisture transport coming from underneath. I therefore agree with earlier comments re benefits of a ground vapour barrier.
    2. Furthermore, the hit-n-miss battens around the perimeter are fitted with hardly any space in between. Hence the subfloor space qualifies as ‘fully enclosed’ and therefore needing a ground VB even more.
    3. It is hard to see on the photo but the flooring appears to be a particle board. If it is, then it is highly hydroscopic (they did not nicknamed it ‘weatbix’ for nothing!) and therefore largely contributing to the moisture transport. After GVB is fitted the drying of the particle board may result in an unpleasant chemical smell that will stay for quite some time. Therefore it is a good idea to install GVP now so the house would be easy to air over summer months.
    4. Polystyrene insulation under the floor does not reduce the water vapour transport.
    5. Good heating is essential for a house like this. A heat pump is hot ideal due to low drying capacity and low heat output. A wood burner would be a much better option.
    6. The house’ cladding appears to be a fibre cement board which is also a water absorbing material and could further contribute to the moisture issue.

    Regards,
    Gleb

    October 16, 2014 at 3:19 pm #1976
    philgregg
    Participant

    Thanks Gleb, This is fantastic info, giving me a wider view of not just Moisture but the consequences that may follow due to building materials in play.

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