My first question was what sort of wood should I use?
I found Plenty of Internet sites that advised on the varieties of wood that could be expected to withstand the rigours of the British climate. So I drew up a fist of suitable types and started to phone round local timber merchants. The species I decided to purchase was Idigbo, an African hard wood. Cost and resistance to decay, were the main factors affecting my decision. I know softwood is the choice of the environmentalist at the moment. However I feared that using softwood might mean the fruits of my labour turning to compost after five years.
Next, do I have the skill and know-how to make my design a reality?
I judged that the most difficult part of the project would be to fabricate the arch forming the top of the doorframe. To minimize costs I wanted to buy the timber in bulk rather than in bits and pieces. Therefore it was important to answer this question before making any such bulk purchase.
The circumference of the doorframe arch dictated that the width of the timber required to produce a blank (from which the final arch could be machined) would be over 200mm. The blanks would also have to be of a precise thickness. Not having access to the expensive machinery required to thickness timber, I would have to purchase this service from the timber merchant. The price quoted locally for the machined timber in Idigbo and other hardwoods was horrendous. Unsure if I was capable of making the arch, I felt I had to compromise and so bought "joinery-quality" Red-Deal, a pale colored pine softwood.
Before starting the arch I was fortunate enough to talk with a close neighbour who had been a carpenter before retirement. He advised me that the shape of the timber blank could best be achieved by laminating several thinner sections. This would allow the 2 joints necessary, to be staggered, improving the overall strength.