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EPDM prep

Discussion in 'Roofing and Guttering' started by Notch7, 24 Mar 2019.

  1. Notch7

    Notch7

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    Im doing a garden office / cabin in EPDM (Carlisle Syntec brand)

    The rubber has a film of silvery dust on it -I guess its a release agent like talcum powder to stop it sticking.

    Im wondering if the rubber needs washing to clean this off before sticking down to the roof.

    Im using the waterbased adhesive for the flat areas and contact adhesive for edges and upstands.
     
  2. Mw Roofline

    Mw Roofline

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    As long as you glue both the timber and the rubber, all you need do is brush the talc off with a soft broom.
     
  3. Notch7

    Notch7

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    Great thanks for that.

    The glue Ive got is this water based deck adhesive
    https://www.rubber4roofs.co.uk/shop/epdm-water-based-deck-adhesive

    Is that the right stuff and can I put glue on both parts like you say?

    Or should I be using contact adhesive -ive got that for the upstands and around the perimeter.

    Cheers Notch
     
  4. foxhole

    foxhole

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    Water based on deck, upstands and edges -contact adhesive.
     
  5. geraldthehamster

    geraldthehamster

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    Correct me if I'm wrong, but don't you only need to glue both roof and rubber for the edges, where you're using contact adhesive? I just applied the water-based to the deck, with a roller.
     
  6. Notch7

    Notch7

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    Did you find the water based deck adhesive stuck well?

    And did your rubber have this silvery dust on it?

    Im gluing onto OSB board
     
  7. geraldthehamster

    geraldthehamster

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    Yes, it stuck very well and is still stuck four years on. The important thing is for the OSB to be absolutely dry.

    I do remember a small dusting of talc here and there, but I didn't do anything about it.

    I'd like to see a reply from MW Roofline, because he is a roofer and I am not.
     
  8. Mw Roofline

    Mw Roofline

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    We started doing epdm roofs when they came on the scene in the uk about 15 years ago and the firestone training video said glue deck and rubber. Then Permaroof changed it and said only glue deck but cause we’re set in our ways we’ve carried on doing both because we think it’s easier for the glue to prematurely dry with dust and talc if glued onto the deck only. Best thing is you do whatever the instructions are and don’t listen to us!
    Saying that we stopped doing rubber roofs about 5 years ago because there is always someone cheaper now that Dave the greengrocer can buy direct and watch a video on YouTube.
     
  9. Notch7

    Notch7

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    Thanks for that -really useful. Ive got some biggish offcuts so I think I will try doing both deck and rubber and see how that works.

    I will also brush off the talc as best I can -see if that helps.

    I can appreciate your comment how its not a great product for pros to use now that DIYers and Dave the greengrocer has access to videos and material suppliers.

    I imagine it means pros probably move towards products like Sarnafil.
     
  10. catlad

    catlad

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    Video's or youtube Iv'e seen some bad diy efforts on the rubber roofing over the years, I only ever glue the OSB. deck if I am using water based adhesive.
     
  11. Notch7

    Notch7

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    Do pros use the waterbased for fixing the rubber to the flat areas?

    I have wondered if pros use a different glue -I seen some pro jobs where the rubber has no wrinkles or bubbles whatsoever.

    Ive got the rubber laid in place loose, Im hoping some sunshine will make it sit flatter.
     
  12. catlad

    catlad

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    Iv'e never had any problems using the water based glue
    just make sure you mix it well.
     
  13. Vinty

    Vinty

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    The white water based adhesive is used on new wooden decks, as this type of adhesive takes a bit of time to cure this allows you to brush out any bubbles or wrinkles when you roll the membrane onto the deck.
    The edge drips and upstands are stuck with contact adhesive.
     
  14. BathDIY

    BathDIY

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  15. geraldthehamster

    geraldthehamster

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    I've done two flat roofs (20 m2 and 25 m2), water based adhesive to the deck, not a ripple or bubble in either of them. There are videos on Youtube and here: http://www.rubba-seal.co.uk/

    Laying out the EPDM to lose its creases is good practice. All the better if the sun is on it. Ideally you want dry sunny days to ensure that the OSB deck is nice and dry. I think damp is the biggest cause of poor adhesion.
     
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