Hi,

This is a trial to see if I can figure out how to post digi pics on the TFG Forum (doh!).

The first one is of a thatched (long straw) 3 bay box framed house made from oak and elm. That's me pointing out various building features to the recording team.



The next one is of an early 15th century 4 bay cruck hall where one end has been raised to provide better headroom on the upper floor. The right hand end is the original roof profile. Do you see the straw rats running up the thatch ?



And finally here is a mid 15th century 3 bay end jettied open hall house that has been underbuilt in brick.



Any observations, questions, comments ?

Regards

Ken Hume

Great post, Ken!

Pictures came through fine. Looks like you have a quality camera. Thanks for taking the time to figure out picture-posting. Pictures add so much to posting here.

Those rats in the second picture...were they part of the recording team?

I thought I heard an old story once about barn yard animals, such as cats and dogs, being able to climb up onto thatched roofs and rest. Then when a surprise rain storm came up it would wash these sleeping animals off the thatched roofs. And that was where the saying that "it's raining cats and dogs" came from......

Very nice Ken, keep em coming!

Ken,

Are the timbers in the last photos painted or treated with something to get to that color? Is there some traditional mix beyond time?

Brad

If I might tag on with more questions. I don't see any bracing on two of the homes, is the infill structural? How do you keep the infill from deteriorating the timbers or does the limewash act as a preservative? At the junction of the timber and infill it seems like there would often be an air leak, does this not cause a condensation problem there? The pattern at the ridge in the top shot is really nice.

Hi Brad, Don & Mark,

The timber frame of the 3 bay box frame (top pic) was until recently covered in a lead based paint but this was detaching in layers and so was removed by the owner. All the timbers that you can see (and those that you can't see) in that pic are elm except the storey posts which are oak. The jettied house is coated with a pine tar distilate which seems to have been popular for a period but not done much these days. It hides a multitude of sins and brings a uniformity to old framing. Some very old timbers just go black (without painting) and its difficult to say exactly why this happens.

The box framed house originally had more bracing that you can shake a stick at - it had 12 windbraces (6 now missing) and 11 long wall braces (1 never fitted on rear wall due to conflict with a scarf joint in the wall plate, and 8 cross braces (4 now missing). The outside wall bracing is set back from the face by a couple of inches and when covered with daub gives the impression of a sans brace building. As Don notes the jettied house in the lower photo has all of the main framing faced to the outside including the braces. This house has a higher oak content but still has many primary timbers made of elm.

I have yet to do a full survey on the the cruck frame for long wall bracing and obviously cruck frames don't need cross bracing but this would most likely originally have been fitted with wind bracing. When the front roof was raised the windbracing would have been lost on one side as an upper floor through way was created. Many buildings like this now derive most of their structural rigidity from either the wattle & daub panels or later brick infil noggin.



The best infil panel for timber frame is wattle & daub. Recent thermographic photographs taken of the box framed house in mid winter demonstrate that later replacement single skin brick noggin panels were loosing heat at a faster rate than the original daub panels. These panels are only 4.5" thick. Daub panels have the added benefit that they are simple to maintain and remake. The gable truss panels in the top box frame were all replaced by the owner by himself. Its not possible to say with certainty how gaps were cured when the frame was new and drying out but the simple answer might be that any gaps that were opening up were simply raked out and then daubed up again around the edges however I have seen no evidence of this practice. Limewash would have been applied on top of the daub creating a weather coat and this wash tends to find and fill gaps and cracks. Limewash appears to have preservative effect as does layers of soot build up from open hall or smoke bay fires.

I have now prepared a full 3D model of the box frame cottage and am currently experimenting to see if I can produce an equivalent X Ray specs Sketchup view to that shown in the photo. More of this later.

Regards

Ken Hume

What is the make up of the daub? Is it clay or loam or a mixture, dung, straw, sand, perhaps blood and sweat. These materials in combination with the lime have a drying quality, clay on its own works similar to lime in that it wicks moisture away and dries quickly. Concrete does just the opposite, it attracts moisture and holds it, perpetuating that 3 letter word, ROT.

What is the climate, is it wet and warmer, temps, cold, does it ever snow? Things seem to be quite lush but still some trees have no leaves. How does the climate effect the ability of these buildings to withstand? Maintenance goes a long way, too.

Ken, these are great photos and comments, thanks.

Tim

Hi Tim,

The climate is temperate with about 28" rainfall per year. It does snow from time to time in winter but not a lot. Damp, mould, decay and rot would be the major enemies of this type of building. The front face of the box frame in the photo is facing north and is thus sheltered from the prevailing westerly wind and rain and hence has survived intact. The south face has deteriorated quite badly and has been rebuilt in places especially below the mid rails.

I can establish the original daub composition since the current owners replaced some of the panels but I will need to ask and await their reply.

Regards

Ken Hume

I am not sure where I read this, maybe in Sobon's yellow book, there was an issue with shrinkage with the lapped dove tail on the bottom of the tie on english tying joints. For some reason here in America there was more shrinkage than in England, therefor the cog was use more frequently, shrinkage not being as much of an issue. Is this true, has anyone read this before?

So, daub is the preferred infill? Have you heard of "stud and mud"?

Tim