With an increasing number of roofing underlays available on the Irish market, it is important to take care when specifying which membrane to choose for your project. If you have any concerns, get in touch with our team and we will be happy to help answer any questions.
Anyone intending to use high performance underlays should ensure they are suitable for use in Irish climatic conditions and that the material is fitted in accordance with the requirements of the manufacturers instructions, the independent certificate, the building regulations and code of practice requirements.
Not all underlays are equal. Before deciding on an underlay it is important to check the following:
- Does your underlay have independent certification?
- If so is the certificate from an official certification body which is recognised in the country in which you are building?
2. Restrictions on use:
- Is there a batten gauge restriction because of poor wind uplift performance?
- Does the independent certificate cover wind uplift or has the test been overlooked?
- How long can the underlay be exposed to UV rays before the roof needs to be covered?
- Does the membrane require a proprietary uv stable tray to be fitted at the gutters under the
- Is a vapour barrier required to be fitted at ceiling level?
- Are counter battens required?
- If it is a breather membrane, is the vapour resistance 0.25MNs/g or lower?
- Is the membrane laid taut or loose?
3. Additional Requirements
- What are the roof ventilation requirements?
- Is additional ventilation necessary above Building Regulation or British / European Standard
- What are the details at the Ridge, Hips and Valleys?