Installing Metal Roofing
on a kit home

Professional roofers installing metal roofing will tell you how difficult this job is. But not when the iron is pre-cut and the amateur roofer so determined. Metal roof installation can be easily achieved via a systematic process, with straight and true roof lines as a result. I did it myself with 'No Help'. I lifted (slid) the iron onto the roof, positioned it and screwed it down. If you are a sole worker you just have to nut out the process, choose a still day (no wind) and take your time.

Of course if you hire help it will go on in half the time, if you have a time limit. But half the time costs twice the money. You do the math sunshine. A modern corrugated roof is a cost effective and obtainable option for the kit home builder. Obtainable, because you can build it yourself with little or no help. To learn how to install metal roofs you need to first understand the components you will use.

Types of roofing profiles

steel roof product

The familiar roll formed shape of a corrugated roof dominates most non-tiled houses of the 80s and 90s, but this decade saw the rise of more angular profiles and more use of aluminium. Less folds and more height in the rib allow greater spans with less support, hence less building cost. They also offer lighter weight and require less fall to move storm water.

Advantages of steel roofing

• Lightweight and portable
• Durable and long lasting, especially when coated in modern finishes
• Large range of profiles and designs
• Fire and spark resistant
• Recyclable
• Labour efficient

Roofing materials supplied

1. Steel roofing cut to length
2. Various length metal roof screws
3. Barge capping
4. Ridge capping

All of these roofing materials are in pre-selected bonded colour.

Installing metal roofing

You will need good gloves, sun lotion, hat, 18volt+ cordless drill with a tech screw driver bit for metal roof screws, chalked string line, tape measure, and if you have hips and valleys etc you could use a cordless nibbler.

To prepare for the corrugated roof we have installed the trusses, fascias, guttering and insulation . If you are a lone worker, try to work out how to slide the corrugated roof sheets up onto the roof safely and without damaging the gutters. I rigged up a movable bracket lined with carpet!! I pushed up 8 metre (8.5yd) sheets without any problems. Took me twice as long admittedly, but I had more time than money so... all I had to do was pick low wind days.

I had a couple of strategically placed ladders up inside the roof framing and used them to gradually move the sheets up the trusses. Before you lift your sheets, turn up the lower ribs with a shifter, this will prevent water blowing back under the ridge cap. The prevailing wind should determine your sheet laying path ie start at the opposite end to where the wind comes from.

Check you have all the roofing materials at hand and ready to install. Push your first sheet over to the gable end and set it up flush with the end of the roof batten and parallel with the gable fascia. Check that the sheet hangs 50mm (2") into the gutter and is just short of the apex. Secure the sheet with metal roof screws 3 ribs from the gable (that's the 'high' rib). The edge will be secured with the barge capping later.

Overlap the sheets one and a half laps (corrugations) or as specified with other profiles. Every second sheet measure across apex and base to make sure your sheets are straight. You can also mark off the battens every metre to keep track. The pattern for normal wind areas is a metal roof screw every second rib along the base, and every third in the middle rows. Leave the top until the ridge is on.

Installing barge and ridge capping

Gable end profile

Barge capping is installed first over two or three ribs and down the fascia. Depending on the style you want, cut the ends adjacent to the guttering. Screw the capping down through each batten.

Ridge capping comes in maximum 6 metre (6.5yd) lengths and should be started at the same end as the roofing was started. You will have to make a decision here whether to get a pro to scribe and cut the cap so it sits nicely in the corrugations, or have a go yourself. You can also decide not to cut the cap and instead insert precut corrugated foam sealer. If you do decide to cut the cap, lay it on the apex and clamp it in the exact position you want to install it.

Mark out the centre of each corrugation on the cap. Make a template of stiff cardboard or plastic that exactly replicates the curve of the cuts you need to make in the cap. Start with the least visible side of the ridge on your first try. Use a nibbler or a very sharp and curved pair of tin snips to cut each curve out of the cap. It is a good idea to touch up the cuts with coded paint to inhibit rust. The cap is then attached with metal roof screws into the batten every second rib.

There you have it, I'll have you installing metal roofing like a pro sooner than you think. Here is a picture of my finished corrugated roof.

Corrugated roof complete

At this stage of your kit home building you should throw as much gear under roof as possible. Our next job is installing the windows and doors.

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