175mm Z Purlins

This installation guide provides general advice on how to install a single skin sheeted metal roof. The advice within this installation guide is of a limited nature and should only be used as a guide its not be relied upon as an exact instruction on how a roof should be safely installed which will vary with circumstances.

We have a skilled team of Customer Service advisors who will be happy to assist you with any installation queries you have, please feel free to call them on 01837 659 901. Cladco Profiles accepts no liability for any loss or injury caused by any reliance placed on this guide.

Cutting Sheets On-Site

Cladco Profiles will deliver your sheets to you at the exact size you need them, so providing you send over the correct measurements, you shouldn’t need to cut them yourself. We do understand, however, that sometimes this cannot be avoided, and you may need to further trim your cladding. In this instance, we have some recommendations which should aid you in cutting your sheets effectively in the shortest amount of time possible, with no mistakes.

If necessary, we recommend seeking advice from a professional prior to cutting sheets.

Firstly, you’ll need to ensure you take measurements of the roof, so you know exactly how much you need to cut. Never guess this step, it could end up being a costly mistake. Mark the cut-lines with a felt-tip pen or a Sharpie: a pencil won’t do this time.

If you need to cut your roof, we always recommend doing so on the ground. Cutting metal while on a roof is dangerous and could result in serious injury. Lay your profile sheets face down across padded supports. Doing this will stop scratching and will make the process much easier.

When choosing your tools, If necessary, we recommend seeking advice from a professional. You may wish to use a tool that will produce as little heat as possible. Heat can damage the coating on the sheet and thus cause discolouration, scratching and in some respects could ruin your anti-condensation felt attachment. For longer, straight cuts using a circular saw with a fine-tooth metal cutting blade that produces a cold cut is often advised. If you only need to make smaller cut-outs and openings, or for cuts that are not straight, a jigsaw or reciprocating saw may be recommended by a professional.

In some instances, you may be recommended to use an angle grinder with a small tooth blade or disc when cutting metal classing. Reciprocating nibblers are widely used in the roofing trade, and these produce an excellent, clean cut.

As you can see, there are a wide variety of tools you may wish to use when cutting sheets, however you must always seek advice before cutting from a qualified professional. Cladco accept no responsibility for any injury or accident that may have occurred by using the above tools. We do not recommend any specific tools but recommend the advice from a qualified professional.

Remember to remove any swarf with a brush to prevent damage to the sheet.

Lay Sheets

At Cladco, we want to ensure that once you’ve purchased our roofing sheets that you know exactly how to lay roof sheets, tile sheets and more in the preferred way. Laying metal sheets in runs is normally the best way to achieve this and we recommend by starting at the eaves and in the corner away from the direction of the prevailing wind (If it’s a single sheet run). This will help prevent side laps facing into the wind and water ingress.

We recommend when laying your first few sheets to not fully fix them until you are sure they are correctly aligned. This can help mitigate the impact of any false starts to begin with and only once you are sure, is it best to put the remaining fixings in and carry on with the build.

Laying Box Profile Roof Sheets

For a single pitch roof the minimum pitch we recommend is 4-5º. Lay Box Profile sheets in runs. Start at the eaves and in the corner away from the direction of the prevailing wind (this will help to prevent side laps facing into the wind and water ingress). If the first sheet is not laid perpendicular to the eaves and ridge, adjustments will have to be regularly made when laying other sheets and a ‘saw tooth’ effect at the eaves will be seen. This may be unavoidable if the building is not square.

The first row of sheets should extend over the bottom purlin and the eaves so that rainwater can drain into a gutter or beyond the wall.

Sheets should be overlapped by the next sheet in the run by at least one profile or corrugation (‘side laps’).

Please note – maximum length of sheet we can supply is up to 9m. If you require a longer length, you will need to do a 2-sheet run as per image above.

You should always overlap the sheets by at least one corrugation. When overlapping sheets its recommended to use mastic lapping tape.

For side laps. It is good practice to use mastic lapping tape and stitching screws to ensure a robust weather resistant joint on side laps. Lapping tape with a section of 9mm x 1.5mm mastic should be run along the crest of the profile that is to be lapped, sheet to sheet stitching screws should then be used at 600mm intervals down the lap to consolidate the bond created by the lapping tape.

For end laps a minimum sheet over sheet overlap of 250mm should be allowed for where sheets lap, this lap must be supported underneath by a purlin. As with side laps, it is good practice to use lapping tape to help create a robust weather resistant joint. A strip of tape should be placed across the full width of the lap approximately 25mm from the end of the top end of the overlapped or bottom sheet. Lapping tape is considered more effectively than silicone.

How to Lay Tile Form Roof Sheets

For a single pitch roof the minimum pitch we recommend is 12 degrees Tile Form sheets must always be laid from right to left. When laying the first sheet it should be offered onto the roof to get the purlins in the correct place as when fixing the sheets, the screw will be in line with the purlins. Screws and purlins will match, fixings go just under the tile drop (curved aspect of sheet pattern)

Please note – maximum length of sheet we can supply is 5m. If you require a longer length, you will need to do a 2-sheet run.

If a two-sheet run is required, lay the sheets in this position and use the same fixing instructions as above.

Tile sheets have to be laid from right to left sequence, starting on the right-hand side of the roof laying on the next sheet to the left, lapping over the profile with the small gully detail on the last lap of the left of the sheet.

You should always overlap the sheets by at least one corrugation.

Tap each new sheet tight into place where it laps before the fixings and mastic tape are used. We suggest using a soft wood block and a mallet with some rag between the block and the sheet to prevent damage the sheet coating.

How to Lay Corrugated Roof Sheets

For a single pitch roof the minimum pitch we recommend is 10 degrees. For a single run of sheets start at the eaves and in the corner away from the direction of the prevailing wind (this will help to prevent side laps facing into the wind and water ingress). If the first sheet is not laid perpendicular to the eaves and ridge, adjustments will have to be regularly made when laying other sheets and a ‘saw tooth’ effect at the eaves will be seen. This may be unavoidable if the building is not square.

The first row of sheets should extend over the bottom purlin and the eaves so that rainwater can drain into a gutter or beyond the wall.

Sheets should be overlapped by the next sheet in the run by at least one profile or corrugation (‘side laps’).

Please note – maximum length of sheet we can supply is up to 5m in 0.5mm thickness and 6m in 0.7mm thickness. If you require a longer length, you will need to do a 2-sheet run as above.

You should always overlap the sheets by at least one corrugation. When overlapping sheets its recommended to use mastic lapping tape.

For side laps. It is good practice to use mastic lapping tape and stitching screws to ensure a robust weather resistant joint on side laps. Lapping tape with a section of 9mm x 1.5mm mastic should be run along the crest of the profile that is to be lapped, sheet to sheet stitching screws should then be used at 600mm intervals down the lap to consolidate the bond created by the lapping tape.

For end laps a minimum sheet over sheet overlap of 250mm should be allowed for where sheets lap, this lap must be supported underneath by a purlin. As with side laps, it is good practice to use lapping tape to help create a robust weather resistant joint. A strip of tape should be placed across the full width of the lap approximately 25mm from the end of the top end of the overlapped or bottom sheet. Lapping tape is considered more effectively than silicone.

Tap each new sheet tight into place where it laps before the fixings are used. We suggest using a soft wood block and a mallet with some rag between the block and the sheet to prevent damage the sheet coating.

Side and End Laps

When you’re looking to tackle side lap roofing, it's good practice to use mastic lapping tape and stitching screws to help ensure a robust weather-resistant joint on side laps. Lapping tape with a section of 9mm x 1.5mm mastic should be run along the crest of the profile that is to be lapped. Using lapping tape is considered to be much more effective than using silicone and will help align the lapping perfectly at the first time of trying.

Sheet to sheet stitching screws should then be used at 600mm intervals down the lap to consolidate the bond created by the lapping tape. This way, your side lap roofing will be made to last and be as robust as possible.

Side Lap Roofing & End Lap Joints

For end lap joints, a minimum sheet over sheet overlap of 250mm should be allowed for where the sheets lap. This lap must be supported underneath by a purlin to be secure and long-lasting.

As with side lap roofing, it's good practice to use lapping tape to help create a robust weather-resistant joint. You should use a strip of tape placed across the full width of the lap, approximately 25mm from the end of the top end of the overlapped or bottom sheet. At Cladco, we recommend using the mastic tape wisely as it is very difficult to separate the roofing sheets once they are joined by lapping tape. Always make sure of where the sheet is positioned before placing one sheet on top of another, this way you’ll get it on the first attempt.

Side Lap Roofing & More at Cladco

At Cladco, we want to ensure you can complete any project efficiently and quickly, which is why not only can we help you with any purchase, but our Help and Advice section will keep you informed long after your purchase with us. From how to handle sheets, cutting sheets on-site or even ongoing care of your roofing, we can help advise on the best ways to do so.

If you have any questions regarding our products at Cladco Profiles or have any queries regarding using them, don’t hesitate to contact us via phone or email. One of our expert, friendly team will be able to assist you and help in any way they can. Alternatively, read through our FAQs for common answers to questions we receive.

Create a Purlin Framework

Purlins can be used create a supporting framework and to transfer the loads imposed by the metal sheeting onto the primary building structure. Purlins can be fixed to rafters using boltable cleats.

As a rough guide purlins should be at least 50mm wide to ensure sheets can be easily fixed, and in the case of 0.7mm thickness sheeting, be spaced no further than 1.2m apart. 1m apart in the case of 0.5mm thickness sheeting. Exact requirements will vary if in doubt we suggest obtaining advise from a qualified professional.

All purlin joins or laps should be supported by a rafter.

Once purlins have been fitted and a supporting framework created an inspection should be carried out before any further work is carried out. A full apropriate safety check should be carried out, It should include but not limited to:

• the purlin framework is correctly aligned and levelled;
• purlins are correctly spaced and within specified tolerances;
• there are no protrusions e.g. bolt heads on the face of the framework.

Ridge Caps

Lay ridge caps from the opposite end of the roof to the direction of prevailing winds. Each cap should be overlapped by the next cap in the run by a minimum of 150mm.

We recommend ridge caps are fixed using self-drilling TEK type stitching screws to the high point of each profile they cover and through the appropriate ridge filler if one is being used. This helps ensure a robust weather resistant joint as wellas keeping out birds and vermin.

Handy Advice: - When constructing your purlin support structure you may need to consider additional purlins to support your ridge caps and other flashings.

Protrusions

Please note:

This installation guide should be used a guide only. This information provides general advice on how to install a single skin sheeted metal roof. The advice within this installation guide is of a limited nature and should only be used as a guide its not be relied upon as an exact instruction on how a roof should be safely installed which will vary with circumstances.

We have a skilled team of Customer Service advisors who will be happy to assist you with any installation queries you have, please feel free to call them on 01837 659 901. Cladco Profiles accepts no liability for any loss or injury caused by any reliance placed on this guide.