HOW TO INSTALL RURAL RETROSEAL STEEL

The major problem with using profile cut flashings is shrink and creep of the wall sheets. This may be due to deliberate shrinking or expanding of the sheets, or sheets being pulled apart or pushed together at the joint by installers to run plumb with the building, or to finish sheeting in an ideal position for corner flashings etc. It can also be caused by sheet and roll-mill variations.

Rural Retroseal addresses these problems in several ways:

1. The flashing is made in sheet widths, so the creep or shrink of each wall sheet doesn’t progress. However, it is slightly longer to allow for overlapping.

2. The tabs have a unique shape and length, and are set at such an angle from the main body of the flash that they can create pressure where they meet the sheet profiles. Where the sheet is in shrink (the profile on the sheet is deeper) it flexes down into the relaxed position. On creep (the profile on the sheet is shallower), it flexes up to the pressured position.

3. Cutting and lapping

Fitting and Fixing Details

With the tab profiles up, position the flashing into the sheet profiles, with the fingerlip touching the floor. Ideally the tabs on each flashing length will sit centrally in the sheet profiles.

Where this does not occur, with high profile products such as Trimdek, Monoclad etc where two profiles fit neatly, and the third and fourth profiles are slightly off-centre, cut it in half between the  2nd & 3rd profiles. In the case of corrugated, cut the flashing at an appropriate place to allow the tabs to fit naturally into the profile. Overlapping is OK.

A few dobs of silicon under the fingerlip may be used as a securement. However, the flashing can be fixed more substantially at its vertical face to the sheet pan area by a 10/16 tek screw or equivalent, particularly if a gap exists between the edge of the concrete and the wall sheet (can cover up to a 27mm gap).

One of the best ways to do this is to drill a hole from the inside out with a smaller bit than the screw being used (while maintaining a position to effect the neatest finish), with a second person screwing a tek back from the outside, using the hole as a pilot (careful not to overscrew). The ideal screw position is beside the sheet profile for high profile sheets, and in the valley for corrugated sheets. Use enough screws to achieve the desired finish. Pop rivets have also been used successfully.

If the tabs on the flashing don’t conform to the inside of the  sheet profile, a light tap with a hammer will usually remedy this.