Choosing a roof covering that will still suit your home in years to come

Consider the proportions of the building. A broad, exposed slope has a greater visual impact than a small roof tucked behind a parapet. Eaves width, dormers, chimney and window shapes all matter. A covering that suits a simple barn can look quite different on a house with several intersecting slopes.

Collect a few examples with a similar building shape and roof pitch. Examine the spacing of the ribs and the way the edges are finished as well as the colour. This makes it easier to tell which features you can reproduce on your own home and which owe their effect to the photograph.

T18 and T35 sheets form parallel lines across the slope. Their straight ribs can suit restrained architecture and agricultural buildings. A shallower profile gives a finer pattern, while deeper ribs cast stronger shadows. Look at the cross section of the actual product to judge the effect.

When the roof and metal façade share a colour, detail their junction separately. Show how rain leaves the roof, how the flashings meet and where air enters or exits. These details allow the roof and wall to read as one form while each performs its own function.

Tile-effect steel ranges from shallow, regular courses to strongly embossed profiles. Match the scale to the size of the slope. A deep pattern on a small roof looks different from the same pattern on a large house. Smaller modules are easier to handle, while the pressing determines much of the visible pattern.

On a simple slope, sheets cut to length can give regular courses with fewer end laps. The support must be even and the first sheets accurately aligned. Check the course lines against the eaves early, as a gradually widening deviation becomes conspicuous across the roof.

View the sample in sun and shade alongside the proposed wall finishes. Graphite, grey and black can have different undertones, and matt and glossy surfaces reflect light differently. A colour code gives only part of the picture. For a large roof, visit a completed building with the same coating if possible.

Include gutters, window frames, fencing and flashings in the colour scheme. Slightly different shades can work together, especially within a restrained palette. Treat the thermal behaviour of the loft as a separate design question, taking into account the roof build-up and ventilation as well as the colour.

A straight ridge, well-proportioned verge flashing and neatly formed chimney junction give the roof clear outlines. Size each flashing to suit the profile. An overly broad trim can draw the eye across the entire slope, so agree on its folds and finish before placing the order.

Exposed and concealed gutters give different eaves lines and require different arrangements for maintenance. Allow room to inspect and clean either design. Keep the ventilation components and safety fittings the roof requires, and show them on the drawings so their appearance can be assessed.

Check the permitted pitch and support requirements before comparing finishes. Specify steel, coating and fasteners for the exposure. Two sheets that look alike may differ in approved applications and warranty conditions. Use the technical data to shortlist the finishes suitable for your roof.

Plan the roof hatch, access walkways, snow guards and any future roof-mounted equipment together. Retrofitting them can add cost and disturb the layout. Agree their positions early so that they work as intended and fit the visible lines of the roof.

Consider how the roof will sit within its surroundings if planting matures, the fence changes or the walls are repainted. Check the availability of accessories and how a damaged piece could be repaired. An unusual finish may take more effort to match later.

Compare complete quotations alongside the samples. Include the cost and extent of the work needed for the details you saw on the drawings. A widely available profile can suit a house for years when the proportions, finish and workmanship all support the architecture.