Overboarding flat roof

Discussion in 'Getting Started FAQ' started by Tracey Ward, Jun 8, 2018.

  1. Tracey Ward

    Tracey Ward New Member

    We've had a quote from a fibreglass roofing company to redo our large felt flat roof.
    They have suggested that they can 'overboard' over the felt to keep the costs down.
    Does this seem reasonable?
    What are peoples thoughts please?
  2. KIAB

    KIAB Well-Known Member

    Nope, always better to strip completely back to joist.
    Tracey Ward likes this.
  3. Dr Bodgit

    Dr Bodgit Well-Known Member

    Per KIAB, strip back to joist, depending on condition of boards either keep or replace.

    You really don't want to be putting a new roof over an existing one, the condition of which you don't know.
    Tracey Ward likes this.
  4. KIAB

    KIAB Well-Known Member

    If it's a roof on a habitable room, then look at a warm roof construction (many benefits) over a cold roof design.
    Tracey Ward and DIY womble like this.
  5. Tracey Ward

    Tracey Ward New Member

    Thankyou for your replies. We're a little concerned if it's going to be a good job.
  6. KIAB

    KIAB Well-Known Member

    Seriosly look around for another GRP firm.:)

    Boarding over exsisting felt, is not good practice.

    Might find a installer close to you in link below.

  7. Beeero

    Beeero Member

    If you want a good job I wouldn’t be using fibreglass full stop
  8. KIAB

    KIAB Well-Known Member

    Now't wrong with GRP, had it 25 years on roof at previous place, not one leak, also got it here, been there nine years, couldn't see EDPM lasting that long.
  9. Tim OSullivan

    Tim OSullivan New Member

    To a certain extent you will get what you are paying for. Felt has seen its day and now Single ply membrane is the way to go , or Glassfibre roof covering seems popular as it gets lots of advertising . The Glassfibre roof covering will sit well on the new ply overlay. But finishing the roof like this might be construed by some as a short cut. I am not personally a fan of the Glassfibre finish. The stripping of the existing roof covering can be a difficult and laborious task, with obvious additional costs. (ie: skip and additional labour, and if the felt is bedded in pitch, Its a dog to get up and the old particle/chipboard will break up - more cost ).
    Also the single ply membrane - there are some inferior products around -I have seen many fail due to poor working practices and poor products - and as its a growing market -the roofing companies are all trying to get on the bandwagon. Do some research- I have been using Tor coatings - Estaseal for 30 years and to me its the best product on the market. Just stripped off my own 30m2 roof today and a few repairs and laid fibreglass re-enforcement in Tor embedment coat . I will get topcoat on tomorrow and a second coat done Sunday if dry. I am confident as I have used this product for years I will not have to touch that roof for 20 years at least .
    Good luck - hope this helps.
    Tracey Ward likes this.
  10. Tracey Ward

    Tracey Ward New Member

  11. Tracey Ward

    Tracey Ward New Member

    Thankyou for your help. I think we need to definately get more quotes in.
  12. BMC2000

    BMC2000 Active Member

    You can use the old felt as a VCL, mech fix or bond insulation board and then fit (my choice!) , Sarnafil with support from the experts http://www.roofassured.co.uk
    Tracey Ward likes this.

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