Glass roof panels

glass roof panelsBesides the materials already discussed in connection with pitched and flat roofs, there are various kinds of glass and plastic roofs. Conservatories, verandas and many types of lean to often have glass roof panels. For purposes of repair and maintenance, these are generally treated as though they were horizontal or sloping windows. Such roofs are prone to excessive heat loss, and they promote condensation. In fact, the condensation can be so severe – with water dripping down continually s that it is sometimes difficult to distinguish between condensation and a leak. The best way to be sure is to observe when it happens. Leaks will occur only during rain; condensation can happen during cold, dry, as well as wet, weather.

To carry out a diagnosis in warm, dry weather pour a little water on the suspect spot and see if it comes through. Besides replacing the roof, there is little that can be done about the condensation, or the lack of insulation. In any event, such glass structures have undoubted advantages, and are part of the period charm of older houses. Leaks can be cured. Keep the putty in good condition. It and the glazing bars should be well painted. Make sure the paint goes beyond the putty and on to the glass by 3mm in a neat line all round to effects a good seal. If leaks persist, a tape is available to seal off the joins between glasses and frames. Be wary of climbing on to a glass roof panels. Usually the glazing bars are simply not strong enough to support a person’s weight. Place scaffold boards, which you can hire, across the roof so that they rest on the wall of the structure at each end. If the strength of the wall is in doubt, the scaffold board should rest on a large stepladder at each end. Take care not to overbalance, or step off the plank. Even if the roof is strong enough to support you, do not put your weight on the glass roof panels.

flat roof repair tips – how to fix flat roof leak

Most flat roof repair tips should pose few difficulties, but the complete refelting of the main roof of a house is a big job and not one to be undertaken lightly. Just as with pitched roofs, you cannot assume that the source of a leak in a flat roof is immediately above a damp patch on a ceiling. Water can run a long way on top of the ceiling before finding a way down. Climb on to the roof to inspect it. The fault might be a local one. For instance, you could discover one or more thin cracks. Seal these with mastic sold for such a purpose at builders’merchants. If you notice bubbles, these are caused when moisture has penetrated underneath the felt and is warmed by sunshine. The moisture expands, and forces the felt upwards, forming the bubble. To remove a bubble, make two cuts across each other, and peel back the four sections formed. Leave them for a short while to make sure all the moisture has evaporated, so this job should be done during warm weather. Bed the felt back in place in a bitumastic compound. Press the cut felt down well, apply more compound on top, then sprinkle on a few chippings.

Flat Roof Repair tips

Holes in the felt can be repaired, provided that you can get hold of offcuts of felt — by no means easy, because it is sold by the roll. Cut a piece of felt about 50 mm bigger all round than the hole. Bed it in bitumastic compound, apply more compound on top, and add a few chippings. Leaky felt may bear no obvious signs of damage. In old faded felt, the likely cause of flat roof leak is porosity which requires waterproofing. At its simplest this consists of the application of a waterproofing liquid, of the type supplied by the companies that specialize in damp-repellents. A more thorough treatment involves bedding a reinforcing membrane in the liquid. These materials are sold at builders’merchants and DIY stores. Clean the roof thoroughly with a stiff brush. If there is any moss or lichen present, scrape it off and apply a fungicide. Ensure that no debris falls into a downpipe, for it might Cause a blockage: to be sure, bung up the top of the pipes. Give the roof a close inspection for small cracks. If you spot any, treat them as already described, then carry out the waterproofing.


Flat roofs construction

Flat roofs construction are usually covered with two or three layers of roofing felt. The top layer has embedded on it a covering of stone chippings, which may be added either at manufacture or during installation. The chippings reflect ultraviolet rays, which could damage the felt. Usually the first layer of the three layers of felt is laid lengthwise in the direction of the slope. The second layer is laid across, and the final one in the direction of the first. Some experts say it is better for all three layers to run lengthwise, provided the joins do not coincide. To ensure that they do not, the flat roofs construction begins laying at one edge and works across to the other, where the final piece is cut to width. The second layer begins at this edge with a full-width roll until the first edge is reached, where the last piece will once again have to be cut to width. The third layer begins at the initial first edge, so the joins in this are kept apart from those of the first and second. In two layer coverings, the first usually goes across the slope of the roof, and the other one lengthwise. Alternatively, both can be laid lengthwise, using the method already described to ensure that the joins do not coincide.


Flat roof constructionThe felt is laid on some form of decking, which can be made up of either planks (tongued and grooved or square-edged), exterior-grade plywood or chipboard, compressed strawboard, or a concrete screed on top of some other form of board. The decking is supported on rafters at centres between 400 and 450 mm. Lengths of tapering small section timber, called firring, are fixed to the top of the rafters to ensure the slope needed to allow the roof to shed rainwater. Insulation and a vapour barrier are incorporated in modern constructions. For general construction of a flat roofs construction, the rafters may be fixed in one of several ways. They can rest on, and be skew nailed to, timber wall plates on the top of the external walls. Where the rafters meet a parapet wall, or where the walls of a lean to join up with the house wall, the rafters can be fixed to a wall plate resting on a brickwork corbelled out of the main wall. They can be supported on a joist hanger, or let into a socket formed by the omission of bricks here and there. On extra-lightweight structures, such as garages and conservatories, they may merely be supported by wall plates bolted to the wall. As with pitched roofs, the ceiling is fixed to the underside of the joists. Plat roofs are often used on single-storey buildings. Reaching them is not much of a problem, and does not require such equipment as access to a pitched roof. For instance, you might climb on top of a single storey extension from a large stepladder.


flat_roofNevertheless, where appropriate, all the safety precautions outlined at the start of this chapter should be observed strictly. The flat roof of, say, a modern town house may not seem as daunting as the slate covered pitched roof of, for example, a turn of the century building, but do not be lulled into a false sense of complacency; a fall from a flat roof can be just as serious. The equipment for reaching the flat roofs construction of a house is the same as for a pitched roof: extending ladder or access tower. Roof ladders are not required, however, and complex scaffolding is seldom necessary, but you will need sturdy boards across the roof.

corrugated plastic roofing – panels and sheets

Corrugated plastic roofingThe roofs of many home extensions designed as sun rooms and conservatories, but not intended as habitable rooms, are covered with corrugated plastic roofing panels or sheets. Corrugated plastic is a long-lasting material, but leaks can develop. Physical damage to the plastic can be caused by heavy objects being thrown or blown on the roof during a gale. A heavy fall of snow cascading from the main roof could also cause cracks lf this occurs, take off the damaged sheet and replace it with a new one. Take a little of the old sheet with you when you go shopping to make sure the profiles match exactly. When fitting the new panels and sheets, remember that each should overlap its neighbor by two corrugations, and that overlaps between the ends of sheets should be at least 150 mm. Sealing washers may be defective. The sheets are fixed to wooden rafters with screws or nails, or to iron rafters with clips. Such fixtures should have a nail cap and a rubber or plastic washer between the head of each nail and the sheet, to stop the rain getting through. These may have deteriorated, or might never have been fixed in the first place. Replace any defective washers; install them where they are missing. You can buy replacement caps and washers, as well as nails if these need renewing. The flashing may have come adrift from the wall, or be defective. You may be able to re-fix loose flashing back in the mortar joint as described in this chapter. If the flashing is defective, buy and fit a replacement. Flashing specifically for corrugated plastic roofing materials is available.  Support for the sheets may be insufficient, in which case they can buckle, causing gaps through which rainwater can penetrate. The only remedy is to provide extra support, and replace the affected sheets.