So... it's taken me longer than planned to cut the frame and in time, my nice straight DF timbers have dried. I've already taken the twist out of two girts with the aid of a scaff pole strapped to one end once the other was housed. This worked for correcting a minor twist, but I've both girts were laid out pre-twist. I'm not sure that I can apply this method to the current one, and I'm scared that if I lay it out on the assumption that I can, then when it comes to fit it, I'll be screwed.

So the issue then is, how to deal with this timber. It's for a girt that has joist pockets and will be ultimately supporting a floor so I'd prefer to not have it two twisty once in place. Right now my best guess is to try and plane the top surface back to true and work from there. The problem is that the top should be a reference surface and I'm not certain that I can plane it to true enough to use it as a reference. I don't have any way of getting a photo online here (working on site), but I'll try and upload a photo of the beast tomorrow night. It's the only really headache that I've had so far, but I can already hear the creaking of the floor that ends up sat on it.

I guess the alternative is to move the problem and just scribe the floorboards to fit... hmm... :-)

Hello,

I don't know how much of a twist you are dealing with, but one way of straightening such an occurrence is to use what is known as winding sticks. Two straight sticks a good deal longer than the width of your beam, placed, one near each end of it and then you eye down the length to identify high and low areas adjusting with the plane until the two top edged if the winding sticks lie parallel.

Anyway, whats wrong with creaking floor boards?, sticky windows, noisy pipes, wavy wall surfaces, sloping floors...

Don Wagstaff

This is the timber.



According to my rough measurements in gimp it's got an overall twist of about 3° (possible a touch over). This is beyond what I think I can take out with brute force, so I either need to replace the timber (not even sure if I can source another... I need to take a look at this), or plane it true on at least one face.

So... cleaning this up is basically a question of planing a bit, then double checking to see what progress has been made. Rinse and repeat? As of tomorrow even I should have access to an electric planer which may make this plausible.

On the bright side, I don't know how much further it can really twist.

It's one of three beams which support a floor between them (Two spans for the joists). If I can use it as the middle beam, then there's no walls that need to meet it, meaning that I just need to worry about the joist pockets. If I have to use it as an edge, then I need two faces which are true in order to get the outside walls to fit!

How long is the timber? 14'or so? That twist in the pic is certainly de-twistable. I once forced a 20' DF 8x8 back to true using the posts it was joined to as levers. The twist was so bad the post at one end was 3' off the deck. Housed joints of course. I would try strapping a long weighted lever to one end, give it a good soaking and let it sit under stress like that for a couple days.

Yes. take a plane, (hand, block, or power) and take your two ends and plane the opposite corners down till both squares sit in the same plane. Try to do this in such a way that it squares you off to another side of the timber if possible. Then take a chalkline and snap a line from one reference square to the other on the vertical side of the timber. Do this on both sides of the timber. If you plane to that line you should get a perfectly flat surface.

Find the center of the twist.. or just use the center point of the stick. Using a 2ft level, or a torpedo level, level this point by shimming either end. Mark where you placed the level so you know where to reference in case the timber gets bumped. Then go the end grain and draw a level line to remove as little wood as possible. If you need to surface more than one face layout a plumb face as well. Then use a chalk line to connect the points. Start planing... you can use the level to check your progress. Plumb and level will always remain constant and square to each other provided that gravity doesn't change. Start by planing across the grain to remove the bulk. Following these steps will take the twist out and straighten it. Hope this helps.

Well, it really doesn't need to be level to gain the lines. Once it is sighted from either end and all four sides have been marked accordingly and the lines snapped connecting the end points it is just as simple as connecting the dots. Yes, put a feather mark in the near center for later use when scribing, if scribing. If you are using snap line rule no need to level it. This doesn't mean you don't have to level it, but it is a unnecessary step.

Tim-

You're right there's no need to level it in order to plane it true. But that's how I do it too. And I think it is faster than you and Gumphri's method with the winding sticks since you don't have to spot true where the winding sticks are in order to get your lines on there so you skip that step.

Jon--

Bottom line is that you can either do winding sticks as Gumprhi said or use a level as denton4th said -- either way works well to get your lines on there for planing the top into a, um, well...plane.

Or try Rays strongarm approach which might work for you (but not all of us are as "persuasive" as Ray).

@Ray Gibbs: The timber is closer to 15ft (around 5m). I've already taken smaller twists out of two girts with the aid of a scaff tube, but I'm twitchy about this much twist.

@The others: Thanks for all the tips. We have an alternative solution (of sorts) which we think might work. We'll need to plane the ends to get a reference (probably). Then (as we're working to square rule) we'll position the ideal timber so that the reference face is essentially outside the real timber, offsetting it downwards. This will move the twist out of the range of the floor joists which means that the floorboards will never intersect with the girt. If I can work out how to attach files, I have a SketchUp file which helps explain this. And here it is!

This of course assumes that I can cut the joist pockets in the correct plane (the ones in the rest of the frame were cut with a router as the faces of the timbers were as near as dammit in the correct planes). Snapped lines to mark the bottom of the pockets should be easy enough to follow. Oh well... I can't claim that I want to do this as a career in the future on the one hand, and get upset about a slightly wonky bit of timber on the other! :-) Enough contemplation. Tomorrow I'll get on with it!

Just to update. Thanks again everyone.

I planed a flat spot in the centre of the beam and stuck a level on it and used that to level up the beam. Then at each end I shimmed a square to level and used a second square to mark out the bottom of the ideal timber (bottom of the tenon in this case) and the bottom of the joist pockets on each side. Then I marked two positions on the top for the width of the tenon. I repeated this at both ends and used a chalkline to join the dots.

One mistake that I made on the first end that I cut was to not join the "ideal timber" lines around the end of the timber before cutting the cheeks of the tenon. Once cut, transferring the line around to cut the shoulder got a lot harder.

The joist pockets have all been cut with a router to the face (so will have some degree of twist in them) and will be tuned to vertical once the beam is in place. The centre joist pockets which incorporate a mortise for a tusk tenon have already been trued up to the flat spot in the timber to ensure that the frame can be put together without too much fettling.

I'm one mortise and two tenons away from lifting the last section of the frame, and I'm no longer scared about what to expect from the ridge beams. Thanks again.