How to Order Custom Flashings for Your Project

A custom flashing is only as useful as the information supplied with it. A short description such as “parapet flashing” or “roof edge trim” may identify the general purpose, but it rarely gives a fabricator enough detail to make a part that fits first time. Knowing how to order custom flashings starts with defining the junction they need to protect, then communicating the dimensions, folds and finish clearly.

For contractors, roofers and homeowners alike, the objective is straightforward: the flashing should suit the substrate, cover the intended junction and provide a neat, practical finish once installed. Taking time to establish these details before requesting a quotation can avoid site alterations, unnecessary joints and delays caused by reworking a profile.

How to order custom flashings: start with the detail

Before measuring anything, identify what the flashing is intended to do. Flashings are used at changes in direction or material, including roof-to-wall junctions, parapet edges, abutments, openings, verge details and transitions around external features. The same broad category can include a simple folded angle, a multi-fold profile with returns, or a shaped cover designed around an existing construction detail.

A photograph of the area is useful, particularly where an existing roof, wall or trim is involved. It gives the fabricator context that a list of dimensions cannot always provide. Include photographs taken from a distance and close up, with a tape measure visible where practical. A simple hand sketch is equally valuable if it shows the face of the profile, the direction of each fold and the position in which it will be fitted.

Do not assume a standard name means the same profile on every project. A “capping”, for example, may refer to a parapet coping-style cover, a head flashing or a cover trim depending on the site and trade involved. Describe the location and purpose as well as the name.

Measure the finished profile, not just the opening

The most common ordering issue is measuring only the visible gap or the width of the surface being covered. A flashing normally needs returns, legs or cover on adjacent faces, so the finished profile is wider than the opening alone.

For a straightforward folded flashing, provide each visible and concealed face dimension in millimetres. State which dimension is the top face, which is the vertical leg and which direction each return folds. If the part has several bends, number the faces on the sketch so there is no uncertainty over the sequence.

Where the profile sits over an existing element, measure the actual site condition rather than relying solely on drawings. Brickwork, render, roofing materials and timber supports can vary from the nominal design size. On refurbishment work, this is especially relevant: old trims may be uneven, walls may not be square and previous repairs can affect the available cover.

It also helps to state whether the measurement is for the outside, inside or centre of the finished fold. A fabricator can then consider the bend positions when producing the profile. If you are unsure, provide a clear drawing and ask for the dimensions to be reviewed before manufacture rather than making an assumption.

Include length, quantities and joint positions

Give the required length of every item and the total quantity. If a run is longer than a single section, show where you would prefer the joints to fall. This matters on prominent elevations, long parapets and roof edges where joint locations affect appearance as well as installation planning.

Where possible, consider how each length will be handled, lifted and installed on site. A longer section can reduce the number of joints, but may be less convenient to transport through restricted access or manoeuvre safely into position. Shorter lengths may be more manageable, although they introduce more interfaces to detail during installation.

Also identify whether ends need to be open, closed, mitred, notched or formed around an obstruction. A square-ended profile may be correct for one junction but leave an exposed edge at another. These small details are best resolved at the enquiry stage.

Show every fold and return clearly

A good profile drawing does not need to be a formal CAD detail. It needs to be unambiguous. Draw the section as if looking at the cut end of the flashing, then add dimensions to each face. Use arrows or labels to show folds, returns and hems where applicable.

For more complex flashings, include the following information in the enquiry:

• the width of every face and return
• the fold direction for each bend
• the overall length and number of pieces required
• any cut-outs, notches, mitres or end treatments
• the intended fixing face or concealed fixing area
• whether the part must align with an adjacent trim, cladding panel, gutter or roof finish

It is worth stating which faces will remain visible after installation. This helps when agreeing the finished appearance and deciding where joints or fixings are least obtrusive. If a flashing is designed to meet another metal component, send the dimensions or section drawing for that component too. A profile that is correct in isolation can still be awkward if it does not account for the neighbouring detail.

Specify material and finish to suit the application

The profile shape is only part of the order. Confirm the material required, along with any finish or colour expectation. Material selection depends on the location, the adjacent materials, the required appearance and the fabrication method. If a particular product, thickness or finish has already been specified for the project, include that information with the enquiry.

For visible roofline, parapet and wall details, colour coordination often has a significant effect on the finished result. Provide the required RAL colour where known, and identify whether the flashing is intended to match existing fascia, coping, guttering, window surrounds or another architectural feature. A colour reference is more reliable than a broad description such as “dark grey”.

It is sensible to discuss the finish before fabrication, particularly where the flashing includes tightly folded features, exposed edges or a prominent corner. The chosen profile design, material and finish should be considered together rather than treated as separate decisions.

Think through installation before placing the order

A custom flashing must be practical to fit as well as correctly sized. Confirm how it will sit against the substrate and where it will be fixed. A fixing return hidden behind another finish may be appropriate in one detail, while another may need a visible fixing face. The installer should be able to position the section without forcing it over uneven construction or interfering with nearby components.

Allow for the roofing or wall finish that will sit beneath, behind or over the flashing. A sketch should show the order of the materials, not just the metal profile. This is particularly helpful at abutments and roof edges, where a flashing may need to accommodate tiles, slates, membranes, cladding or render without creating an awkward termination.

Do not treat a custom-made profile as a substitute for proper junction detailing. Its performance depends on the wider construction, including preparation of the substrate, compatible fixings, joints and the way surrounding materials are installed. Where the junction is unusual or high risk, obtain project-specific design advice from the relevant construction professional before ordering.

Check the quotation against your drawing

When you receive a quotation or drawing for approval, compare it line by line with the information submitted. Check face dimensions, overall length, material, finish, quantity, fold direction and any special end details. Look for apparently minor errors such as a return folded the wrong way or a dimension taken from the wrong side. These can make a profile unusable even when the overall width appears correct.

This is also the right time to confirm whether dimensions are finished sizes and to raise any questions about sections, joints or practical installation. Custom fabrication is based on the approved information, so a careful review before manufacture is far easier than altering completed sections later.

Metal Profiles Ltd can assist with made-to-measure profile enquiries where the required dimensions, application and finish are clearly set out. Supplying a measured sketch and site photographs at the outset gives the quoting process a sound basis and helps keep communication precise.

A simple checklist before you send an enquiry

Before submitting your request, make sure you can answer four practical questions: where will the flashing be used, what does its cross-section look like, how long does each piece need to be, and what material and finish are required? Add photographs, quantities and any details that affect the ends, joints or fixing faces.

Clear information does not need to be complicated. A well-measured sketch, a few useful photographs and a description of the surrounding construction will usually give a fabricator what is needed to assess the profile properly. That preparation is the most reliable way to order a flashing that arrives ready to support a clean, considered installation.