I'm looking to make or buy two timber rose arches for our garden, one to go at the top and one to go at the bottom of a set of not very attractive concrete steps. The steps rise approx 800 mm and extend for some 1800mm in total length I'd like them to be at least as wide as the steps which are 1530mm wide. Most of the ones I've seen are about 1200 mm width rather than the 1800 mm I need. They don't look complex to make so i'm thinking of making my own. Timber selection is not too vital as the plan is to cover with them in vigorous climbers such as Campsis. Anyone done something similar and care to comment please?