b'ARCHITECTURAL SHEET METALContinued from page 10Basically, the roof is sheeted up with a seam landing as close as possible to the curb, then across the low side of the curb, and up the other side, leaving a hole in the roof behind the curb that runs all the way to the ridge (Figure 13).Figure 15Figure 13Soinordertoincreasethechanceofsuccess whenusingmetalroofingonalowslope,start by eliminating all of the places for a metal roof to leak:exposedfastenerspenetratingthebuilding Then, add an eave member down each side and aenvelope; panel end laps (both in the field of the support member down the middle of the hole thatroof and around curbs) by using a site-formed panel runs all the way from behind the curb to the ridgewhenlengthsaretoolongtoship;andbyusing (Figure 14). The support member should be slightlytransverse panels uphill of curbs. Also, use a vertical taller than the eave member so that the transverserib panel as the geometry gets more complicated, panels have a slight crown. Panels are attached topanellengthsincrease,andthenumberofcurbs the eave members and supported in the middle. increases.Finally,considerasymmetricalpanel when the likelihood of needing to open the roof to make a change or replace a panel at a later date is reasonably high. This will save a lot of heartburn.Metal used in this manner can be applied not only in new construction, but to recover an existing metal roof or even an existing externally drained modified or single-ply roof that is on aslope.Figure 14Transversepanelscanbeusedtoraisedifficult penetrations above the plane of the roof, isolating them and greatly reducing the chance of having a leak (Figure 15).12 www.mrca.orgMidwest Roofer'