#STEVE CHAPPELL TIMBER FRAMER FULL#
#STEVE CHAPPELL TIMBER FRAMER TV#

Buttresses can be costly and would not be typical here.Īs stated, it will be a sugar house. The tension rod often defeats the purpose of wanting the clear open space as it's not truly open. Quote from: Brad_bb on March 29, 2016, 04:32:37 PM Yeah spreading is usually the issue, which is why you see tension rods in most done here (US) commercially. With organic timbers, no two will be alike.

#STEVE CHAPPELL TIMBER FRAMER FULL#

If you want a hammer beam bent to impress people, you can accomplish the same effect with a variation of queen or king post bent with organic timbers (natural and sawn on two sides, or full natural). When I first got into timber framing, I was really impressed by hammerbeam bents, but learning about the forces you are dealing with, makes you reconsider whether the headaches or potential ones are worth the extra work and risks. With a larger frame, you're taking chances. I figure if it's a smaller frame, you might get away with no tension rod if you do a few things to direct the force downwards and reinforce to reduce spreading effects. Buttresses can be costly and would not be typical here.įirst ask yourself, why do you want hammerbeam? Looks in a house? Will tension rods be a problem? Most engineers are going to want the tension rods to make sure it won't spread. Yeah spreading is usually the issue, which is why you see tension rods in most done here (US) commercially. There are a lot of very unpredictable forces at work in a hammerbeam, and it wouldn't be a bad idea to have a timber engineer look at it, but I would say that Chappell's advice is generally good as a rule of thumb. A lot of old English hammerbeams are not on posts, they bear on massive masonry walls which resolve those forces and resist spreading. As Chappell says, the braces should terminate low in the post so that all the force is directed into the foundation (as long as your post bottoms are tied in well to channel that force!). Therefore a 10/12 is usually the minimum pitch for a hammerbeam, steeper =better. The steeper the pitch the more force is directed down rather than out. The tie rods actually create a lower chord and make the system a truss.

If they needed metal tie rods, it may have been because their roof pitch wasn't steep enough to prevent speading. I think that it would be foolish to not have a (timber frame) engineer look at it.Īs Dave said, Hammerbeams are complicated! The term hammerbeam truss, is a bit of a misnomer, since there is no true trussing action going on in one of these. It's been a long time since I've looked at Chappell's book, but I would be reluctant to build straight out of the book. It's one of the few times that posts want to bend. There are a lot of hammer beam roofs in the US that have had steel tension rods added after they started to spread. Here is the late great Ed Levin's version, pulled straight out of 'The Open Timber Roofs of the Middle Ages,' The American bracing is spindly, and nothing close to an arch. I don't know where or how the elegant European version got turned into the monstrosity above. The Americanized version is a pretty tacky attempt at the same thing.Ĭompare that to Chilterns link below.

It's worth noting, Chilterns, that those hammer beams sit on top of a masonry wall-one often several feet thick.

#STEVE CHAPPELL TIMBER FRAMER TV#

I suspect the tv and interweb are wrong because they missed the little detail called proper construction. My question, is there a need for the tie-cable/buttress if the construction is done in the way described in Steve's book? Steve's explanation and math make sense and seem logical, but I am planning a sugar house where I will have 3 hammerbeam bents in the middle of the building with a king post bent on each end and want to make sure I'm not missing something. I saw the same thing when searching for hammerbeam designs on the interwebs. On the 'Barnwood Builders' show they visit some resort by a manmade impoundment and in the one timberframe building the host is pointing out the hammerbeam construction (where the braces appear to enter at least half-way, or higher, up the pots) and states there must be tie-cables or buttressed walls. Nowhere does he state the need for a tie-cable or buttress type posts. In Steve Chappell's A Timber Framer's Workshop he covers hammerbeam truss construction and the need for the hammerbeam to be 2/3 the length of the post and that the lower brace should enter the lower third of the post.

Steve chappell timber framer