Waterproof membrane

Preparing a concrete or bitumen floor before laying new laminate is an important step in ensuring a successful installation. Here are some tips to help you prepare the floor and prevent against damp and raising the new floor: Clean the floor: Start by thoroughly cleaning the floor to remove any dirt, debris, or other contaminants. Use a degreaser or a heavy-duty cleaner to remove any oil or grease stains. Remove any old adhesive: If there is any old adhesive or flooring residue on the concrete or bitumen surface, use a scraper or a heat gun to remove it. Check for moisture: Before laying the new laminate, it's important to check the concrete or bitumen floor for moisture. Use a moisture meter to test the surface and ensure that it's below the manufacturer's recommended level for laminate flooring. Install a moisture barrier: To prevent against damp, it's a good idea to install a moisture barrier on the concrete or bitumen floor before laying the new laminate. This can be done by using a roll of polyethylene sheeting or a liquid moisture barrier. Level the floor: Concrete and bitumen floors can be uneven, so it's important to level the surface before laying the new laminate. Use a self-leveling compound to smooth out any low spots or high spots on the surface. Allow sufficient time to dry: Let the surface dry completely before laying the laminate, otherwise, the new floor may raise or warp. Finally, make sure to carefully follow the manufacturer's instructions for installing the laminate flooring. This will ensure that the new floor is properly secured to the subfloor and will help prevent against any issues with raising or warping. Good luck with this project! Lubos

Hi before laying a new membrane in place id paint the floor with fosroc Cm210 a waterproof cementatious slurry id presume the bitumen was acting as the damp proof,but has deteriated over time.if your planing to ley just membrane then a 1200 gauge to avoid puncture and ensure all joints are taped and sealed. I hope this helps

There are many ways of solving damp .it sounds like there is no water poof manbarin or it could be weeping though wall but need to look at to see what's happening . ALFORD BUILDERS.

A concrete floor with bitumen could mean the concrete has a damp issue/ no damp proof membrane underneath and maybe why someone in the past painted it on to suppress the damp. This may have failed and the damp has risen regardless and this is why your floor and laminate might of buckled.