I am often asked what’s the difference between Hardwood and Softwood and will Hardwood last longer?
The first part of that question is fairly straight forward to answer; Hardwood is timber from broad-leaved usually deciduous trees, that is, a tree that looses its leaves each year and belongs to the botanical group angiosperms. Not all hardwoods are hard though, most British species are; exceptions that come to mind are Yew, classed as softwood but nearly as hard as Oak, and Larch, classed as softwood but in fact deciduous. Softwood is a timber mainly from conifers that is a tree that keeps its foliage or needles all year round and belong to the botanical group gymnosperms. But again exceptions do exist, Balsa wood classed as a hardwood is in fact the most soft of timbers.
The second part of the question is not so easy to answer. You certainly would not construct a boat out of Redwood, but Larch a softwood is suitable, I once had a boat constructed out of Larch on Oak that is to say Larch planks on Oak ribs, and the yacht featured on this site was made with Pitch Pine a softwood and 90 years on it is still going strong, on the other hand, a boat constructed out of Sapelli a hardwood would not do at all.
Conversely I have come across timber windows and doors constructed out of softwood that are well over a century old and suffering no adverse effects of rot or decay, and hardwood cills on conservatories maybe 15 years old and rotten through out. There is also aesthetics to consider. So what’s best?
There are certain timbers that seem to be almost bullet proof to what ever situation Teak, Pitch Pine, Green Heart, Oak, four woods that will last, there are others, the first two mentioned are difficult to obtain and certainly very expensive the most readably available durable hardwood has to be Oak, and the most durable softwood that I know of is Pitch Pine.
But the durability of more commonly used woods for exterior work comes down to the paint or stain used and the application of that paint or stain. Its no good giving a door or window that is new wood a coat of one coat gloss and expecting it to last as long as those mentioned earlier it has to be ‘ a built up layered system of paint’ that is primer x2 coats, undercoat x1 coat, and gloss x1. Or for stains at least 3 coats and a further 2 coats after a period of 6months. There after a 10 yr cycle of refurbishment of the paint system applied should suffice.
There are pre paint preservatives that can be applied, a clear wood preservative can be used, and for serious period joinery projects, circular joinery, or carvings the option of ‘vac vac’ or ‘double vac’ as it is sometimes called should be considered this is a clear pressure treatment of preservative that renders the timber rot proof for many years.
So the conclusion is certain hardwoods are by far longer lasting but common softwoods i.e.: Redwood will last many years so long as the correct system of preservative/paint is used.