Choosing a roof covering for a house

Check the drawings for pitch, slope length, valleys and service penetrations. Each product has its own installation limits. A covering specified for steeper slopes still needs that pitch even if extra sealant is applied. Assess the complete roof system.

For reroofing, have a specialist inspect the existing frame. New covering weight is only part of the loading alongside snow, wind and equipment. A light sheet can help with refurbishment, but damaged rafters need their own assessment on site.

Cut-to-length metal tile sheets suit simple slopes. Long sheets reduce joints in the direction of water flow. Careful measurements reduce cuts on site. A gable roof is a good candidate if transport and safe unloading are feasible.

Handle large sheets carefully to prevent distortion. Wind can make lifting them difficult. Dormers and angled edges produce offcuts, so ask for a cutting layout as part of the estimate. Large sheets are economical only where the layout makes good use of them.

Small modules are easier to carry and position on slopes with many changes of direction. Repeated sheet sizes simplify handling. Local repairs may be easier if a matching profile is available. Keep the documentation and a few spare modules from the same colour batch.

Modular sheets need accurately spaced battens. Follow the product instructions because small spacing errors accumulate across rows and open up joints. Compare cover width, lap details and available flashings for the specific module.

Trapezoidal steel gives a regular linear appearance for modern houses, garages and outbuildings. T18 usually has a shallower profile and T35 a more pronounced rib. Decide using the actual product data, support spacing and pitch, and verify capacity for the chosen sheet.

An insulated roof with trapezoidal sheeting needs a designed assembly below the outer skin. An underside fleece may hold condensation temporarily if it can dry out. Habitable rooms still require a complete thermal and moisture-control design.

A roof sandwich panel bonds two facings to an insulating core. It can suit halls, pavilions and heated outbuildings. In a house, design the joints, acoustics, fire protection and finish. A wall panel of the same thickness requires separate evidence before it could be used for roofing.

Clay tiles, concrete tiles and bituminous shingles differ in substrate and structural loading requirements. Compare complete assemblies. A light covering may still need several supporting layers, and a continuous deck can alter the cost significantly.

Develop two or three options compatible with the design. Calculate covering, waste, substrate, flashings and labour for each. Inspect coating samples outdoors for colour and texture. Check warranty conditions and the maintenance needed over the roof’s service life.

A quotation should identify the product and work included, with steel thickness, coating, sales unit and finishing pieces. If an installer suggests a different material, ask how it changes the rest of the roof before deciding.

Check availability of an installer familiar with the system. A late change may require different supports, fixings and flashings. Confirm the variant and details before ordering. For a large roof, ask to see a trial arrangement of the eaves components.