|Posted on Wednesday, November 26, 2003 - 10:26 am: ||
After spending some time reading the discussions on the import of chinese slate and how less expensive they are to buy per square.The thing that has not been mention on this site, is that the slates come in metric sizes.Now we all Know that the U.S.A adopt the imperial measurement.My question to all the slate installers in the Usa is.Do you gauge the slates at metric measurements when you are installing, or are you using the imperial measurement? Most imported slates are holed in metric, which means for every 4 course laid down with a 12x24 slate there will be a gain of approximately 1/4" if measured using the imperial method .Depending on the number of courses the roof has, this could affected the building codes for certain areas and the wind uplift in some areas.Has any body got some imput to this posting .
|Posted on Wednesday, November 26, 2003 - 10:56 pm: ||
We installed a Spainish slate roof they were 20" x 10"-Imperial,These slate are also metric actual Imperial measurement 19.5" x 9 7/8"-We chalked our lines at 8 1/4" to maintain a 3" headlap instead of 8 1/2" for a Imperial 20" x 10"slate.Depending on slope you could Install these slate at 8 1/2" and maintain a 2.5"headlap,If wind uplift is a concern you can always increase your headlap,just order a few extra slate.