Fibrous plaster ceilings also know as plaster glass ceilings, commonly found in older homes is one of those DIY jobs you really need to think long and hard about - do you really want to tackle it? or should you get professionals in. If you've chosen DIY, here's what you'll need to know:
First you need access to the ceiling space, either through the manhole, by lifting roof tiles or removing Tec screws from steel roof sheets. You'll need to be able to crawl through the roofing frame and be able to reach the ceiling where it meets the ceiling joists.
Next you need to clean away all insulation, dust and debris to ensure the new rovings will adhere securely to the fibrous plaster ceiling. Ideally you should use a vacuum cleaner to do this, or at least a dustpan and brush. Once you have a clean surface to work with, the sagging ceiling needs to be supported and pushed back up into position. This can be achieved with a ceiling lifter fitted with particleboard or MDF to spread the load, purpose built props or make your own from plantation timbers. Make sure when positioning your props you use plenty of protection on timber floors, vinyls and carpets.
3) Materials and Tools
Tools for this job will be - ladder, torch, vacuum cleaner, dustpan and brush, scissors, props, dust mask, latex gloves or similar, mixing trowel or scraper and a couple of strong plastic buckets.
Materials - Chopped fibreglass rovings, casting plaster and clean water.
Mix the casting plaster following the manufacturers directions (Tip! Once mixed the casting plaster will start to set after about 20 minutes, depending on ambient temperatures). Take a small handfull of rovings and mix them through the casting plaster. Pour casting plaster either side of the joist where you are going to place the rovings and push them into the mix, ensuring the rovings are fully covered in casting plaster. Your new rovings should be about 200mm to 300mm apart. Let the rovings set for at least 2 hours before moving your props to the next area.
Good luck and remember - safety first! (Always isolate the power before commencing work)