Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)


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!

powered by Surfing Waves

Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.

    • CommentAuthorRex
    • CommentTimeOct 13th 2019
    What ho one and all,

    Sometimes in the UK, we have major weather events that result in flooding.

    My wife is Japanese, and has been following the current typhoon and looking at the numerous flooding photos. Fortunately, her parents are OK.

    But it has me thinking, what would happen to our house following a major flood?

    The house is timber frame with rendered thermolite exterior. A solid poured concrete oversite with 120mm of insulation and UFH set in screed. The insulation is Warmcell with Fermacell internal boards. Some floor to ceiling windows with timber inner frames.

    I'm guessing that the insulation would act like a sponge and all have to be replaced, which would mean replacing all the dry-lining Fermacell. Window frames? As for the UFH insulation, I would guess this would all have to be replaced, which would mean the entire g/f ufh replaced?

    What about the timber frame and sole plates?

    It is a worst case scenario as we do live on a slight slope, but your thoughts would be appreciated.


    • CommentAuthortony
    • CommentTimeOct 13th 2019
    Don’t worry about it if you are on a slope. If you are likely to be flooded or live in a flood plain or near a river — move house!
    • CommentTimeOct 13th 2019
    As Tony says, you likely don't have much to worry about as you live on a slope. How far below you is the bottom of the slope?

    Timber and suchlike is likely to be OK as long as it just suffers water damage. It will get wet and eventually it will dry out again. I don't see why UFH would be affected at all. I don't know about Warmcel. I'd guess it will absorb water and dry out in the same way as timber, but I don't know for sure.
    Houses high up hillsides get flooded by minor streams and ditches, that suddenly turn into major watercourses during extreme rain, our driveway got washed out by one such and we felt very lucky as it could have been much worse.

    When a house gets flooded, the flood is as much mud and silt as it is water, it doesn't much matter what the house is made of, the foul residues drive you out. The insurers end up paying rent for you to live somewhere else, and in the interests of time they will have everything organic ripped out and replaced.
    • CommentAuthordickster
    • CommentTimeOct 14th 2019
    We live next to (50 metres away) a little stream, 100mm deep in summer, 1.3 metres deep at its worst 10 years ago, coming up the garden! We are about 1.2 metres above that level. Built the house on 700 mm high brick cavity wall, then timber and Warmcell upwards. The concrete underneath all slopes to drainage channels to get rid of any floodwater quickly.

    Dread to think how long Warmcell would take to dry. We are a 1 in 1000 flood risk. I reckon that is old money and flood risk increases as time goes on and atmosphere holds more and more moisture of less predictable nature.

    Apparently in spring 1963 with meltwater, we might have got our toes wet.

    The stream is a beast to behold when it gets going!
    • CommentAuthorvord
    • CommentTimeOct 14th 2019
    I had a flood originating from the cold water tank in the loft where they had forgotten to install an overflow pipe. It was a bit of a hassle especially as I was in Sweden at the time. It took out 3 rooms.

    All the permeable insulation had to be stripped out together with carpets, beds, and anything else that could soak up water quickly. Timber frame was fine - wood is very good at drying out when given a little time. I was really lucky to have everything in lime rather than plasterboard so the ceilings survived other than a few cracks that developed to let the water through.
    • CommentTimeOct 14th 2019
    We had a flood from our cold tank in our last house. It went through the gypsum plasterboard ceilings and onto the bed underneath. We were on holiday and when we came back I drilled a small hole in the plasterboard and out came a bunch of water. The plasterboard survived but was bowed for the rest of our time there. The mattress had to be thrown! No other damage fortunately. Our next door neighbour had a more severe plumbing leak and had to take the ceilings down, which was complicated and expensive because there was asbestos in the Artex. Ruined their carpets too.
    • CommentAuthorRex
    • CommentTimeOct 15th 2019
    Thanks for the comments and I am not particularly concerned, just having a 'I wonder what happens' moment.

    I know the UFH / screed would be OK but surely the insulation would get saturated and have virtually no way to dry out. Poured concrete oversite below the insulation and insulation with DPM and screed above. How could that dry out?

    As for the g/f Warmcell, I personally don't think that would dry out. It would certainly compact towards the bottom and I assume therefore leave a big gap at the top.

    And our bamboo flooring would be a goner.
    If the insulation came in contact with brown smelly floodwater containing who-knows-what, you'd probably want to replace it, rather than dry it and keep it as a fragrant memento...
    • CommentAuthorCWatters
    • CommentTimeOct 28th 2019
    Perhaps time to ask if anyone else saw that story a few years ago about an underground parking garage that flooded. For some reason there was thick insulation in the floor and it floated crushing several cars against the ceiling.
    Love to see pictures or a link for that...!

    Much as I want to believe it.... sadly that one does smell a bit fishy. The buoyancy of say 200mm of insulation is roughly equivalent to the weight of 100mm of slab sitting on top of it, even before you stand a few tonnes of cars on top of that. You'd need a lot more polystyrene to float the cars as well. Maybe it was a passiv garage with extreme insulation?

    I'd be less surprised if the whole underground garage floated up and lifted the ground above it- basements are nailed down to resist this.

    On the plus side, maybe floating-immersed garages could be a way to free up more parking spaces in coastal cities?
    • CommentTimeOct 29th 2019
    I calculated that if our site flooded, our house would float on the 400 mm EPS underneath it :bigsmile:

    No idea whether my arithmetic was right, and I suspect that even if it was, the EPS would 'escape' somehow, or tip the house off the side.

    Thankfully, one of the reasons I chose the site was that I think it's pretty unlikely to flood.
Add your comments

    Username Password
  • Format comments as
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   

© Green Building Press