how to frame house roof jump

[constructor]

I’m looking for advice of our experts.
My friends built a country house, a half floor (under the roof there is only one room). It was built by the company. A timber frame house without finishing with roofing. The interior decoration was made by ourselves from the inside by simply put an wooden paneling on the crate. Outside the house is insulated and sheathed by Isover siding. A roof sandwich is: timbers - crate (boards), three layers of roofing material. Now they want to insulate the roof from the inside: URSA and a wooden wall paneling. Why they didn’t make it than, they could save the money, and they just wanted to keep the second floor as summer, and it turned out that there is nothing to breathe in summer, here and decided to do finish. I have a question whether it is right to do warming so? Do I need something else? Besides the roofing there is no waterproofing. Oh, and now they have beaten the onduline roofing.

[expert]

Roofing, of course is not at a place. But once we have it, we need to do a ventilated air gap (well, to sew strips), then a vapor-permeable film type IZOSPAN AM, or IZOSPAN A, then URSA and to cover the inside by the vapor barrier, such as D or better IZOSPAN FD. It is possible to use a common polyethylene, but the savings are little, and a result is much worse. And only then a lining. These recommendations are only acceptable for country buildings.

[bill]

Realistically, if the attic (the space between the roof and the ceiling) is not used for residential care, and it is not necessary to take care of the roof insulation. The only value of the roof is a removal of sediments and inert to the atmospheric conditions. A thermal insulation is used only for residential premises. A thermal insulation of the ceiling done by air layer fireproof porous material, it is necessary to know that the basic "care" of heat occurs with a water vapor from the lower areas located in the gap structures, where is a rotting. The right decision is a heat recovery and a water vapor in the ventilation of premises, it can really save up to 60% of the costs for heating homes ...

[Summer]

In a difficult situation with a choice of cottage. I want to buy a cottage, with no interior finishing. The roof is covered by onduline, but the fact is that under the onduline there is no vapor barrier or waterproofing. Although, everything has been done soundly. Tell me, please whether it is possible to live in a house with a roof or you have to redo something.

[expert]

A decision to finalize the roof of a cottage. You need to answer the following questions:
1. A living will be all year round? If so, you need to decide - whether residential premises will be stationed under the roof? If not living, it is only necessary to insulate a ceiling of the first floor. If there are living spaces, it is necessary to insulate the roof (the thickness of the gable is not sufficient for our winter conditions).
2. A thermal insulation of the roof and gables performed by standard techniques. A sandwich is made: an inner lining, a vapor barrier, an insulation, a waterproofing and wind insulation, an exterior cladding or a roofing. Depending on the materials used for water and vapor barrier, we install a required number of air gaps. For example, for the waterproofing membrane, the gap between a membrane and a roof, and for the diffusion of the film is also a gap between the insulation and the film. The movement of air in these gaps must be sufficient and free, but in this case, your heater will operate as a heater, and not as a sponge for water. Second winter we are under the onduline roof, and no problem. A lot of things depend not on the material, but on a quality of the installation of roof, and kind of team. I have a good roof crew, no problem. And they have some very expensive roofing – a copper, somewhere, something is leaking.

[buldozer]

I go up to the roofing and as usual I have some doubts. Wood of natural moisture, the roof ridge line length is about 5 meters, comb of a roof has a length 9 meters. It is supposed to cover with a metal tile.
So, what matters:
1. Not to tear or skew a design in general?
2. Whether to cover with a metal tile at once (would be a shrinkage)? Probably, I am now interested in how things are done in a mass practice, so, as not to become overly paranoid.

[expert]

It's very easy. The wood shrinks across. Always. Along at a few meters in length. Immaterial. If the rafters are made by the letter A, then it will not happen anything with them. Consider a material of gables. This is more important. Support pediments from the same foam were raised up to 2.5 meters, as for the remaining triangle, I will make probably a frame and trim by some tiles. I, originally, asked the question because personally, I observed effects of shrinkage in a bath of the framework. A minor but noticeable distortion of a sheet roof.
A number of questions on the construction of the roof with a large outflow. House is built of timbers. The sketches present a beautiful roof, a cement roofing tiles, with very large overhangs, resting on pillars. But, this is only a pic.
Tell me, please, how to design such a roof? Especially, I’m concerned with the principal support nodes "roof-pillars."

[baltazar]

-This is another no-costed picture from a magazine.
Such outreach, with this angle of slope, but with rafters (or without linings) under a cement roofing is an utopia!
Posts on a common foundation with a different load or on a separate one, but under a wooden house? In short, it is a wrong decision. Choose another roofing material.
Judging by the number of your posts, you are a builder or you build a lot, then why this test for roofers?
1. This is not a game of testing roofers.
2. The fact that at the moment the construction of such a roof is just a "picture from a journal" revealed yesterday.
3. A foundation for the log house is a warming Swedish tile, "foot" under the posts, high with the basic foundation slabs, but they isolated, judging by the photos. But underneath there no EPPS, EPPS = 50 mm, the sides under a layer of 5-10 cm of sand.
4. If for a constructive and a load, tiles will not do, is there an option of combining roofs? Or no one does it and it will be ugly?
5. Can we make a similar design on the soft tiles?
What could be the solution to be plenty to choose from?
A very likely option, I'll order a professional designer to develop the project under this house, but I want to get to the core of the problem.

[expert]

Columns under canopies have to be very strong, on a good foundation. They have to withstand snow loads and a wind, because the canopy will have a very large sail and gale force winds can easily detach the canopy from the poles and carry out. Fixing the roof with large overhangs has to be done right, for the same reason as the canopies. With the strength of the pillars there is not a problem, a larch of a diameter 280 mm.
Another option to consider.
And can you separate the "overhang" from the "main" roof over the log-house? To not blown away, to cover with "hard" tiles?
PS. It is likely that I ask stupid questions and suggest idiotic solutions but It is important for me to find a right solution.
It is quite possible to separate, as if it "walks" in the winter relative to the house, it will be okay, but the "heavy" shingles will not help during the squalls. You have to do a mount so that when a wind "rises", the roof overhang is not divorced from the pillars and columns are not ripped from the foundation. For a strong wind, the roof as like a fluff.

[constructor]

Without touching the roof, you have two dangerous things:
1.A foundation
2. Posts.
A foundation with uneven loads.
Let's get specific and detailed. This Swedish plate without penetration? Judging by the pictures, the main arm of the foundation is the foundation for the posts? Maybe clever Swedes with their rocky soil (therefore it) is justified, but with our clay soil, you can get in trouble.
The house will have the same weight, but a backwater part of the roof will be another.
That's when you need to calculate the load, when the foundation was poured.
Posts.
As you know, wooden structures have a considerable shrinkage during drying.This shrinkage is not limited to one year. And dries unevenly, first, a south (sunny) side, and at the end is a north part. And then the most interesting:
Pillars of timber you put upright naturally. Wood does not shrink in length. What will happen in your case? The house sits and posts will remain the same height. It is understandable that you will object, between the pillar and the roof will be an expansion and you will adjust the height of them. But the roof will be progress, plus the foundation of the incomprehensible behavior. Of course, you can order a roof design and pass on to them the responsibility and all of their concerns. It is advisable to consult on the expansion joints with boards, not impostors, but with real experienced people and not to dismiss their advice and follow it. About progress in the roof of the house from shrinkage. In any case, your roof "requests" shingles. It is flexible and shifts for it are less critical than for example for the sand one. About the gap you should not forget when laying plywood. A long reach - it's great, beautiful, aesthetic and practical (for the walls of the house), but should be the measure or props on the wall (where there is no poles). This can be arranged aesthetically. And for what you spend on a larch? By the way, I can teach you how to make a decorative hem of conventional needles and a very decent. No additional cost.

[buldozer]

A foundation under the log house does not cause such fear, but the "freebie" under the posts strained at once (just at that moment I was busy again and I believed what builders said – everything was OK!). And there is one caveat. A truss system can be made "moving", but The log house shrinks and top of the vertical posts will shrink too and, despite the expansion, they can stop, IMHO, being vertical. About the "flexibility" of the roof - a few items as a plus of a tiled roof was noted its "mobility".
PS. I am always ready to learn ... The wooden building, moving trusses are a necessity.
And pillars during the house shrinkage will be pressed receiving a bank and the roof will be a sort of a Chinese pagoda.
A foundation under the posts is made individually, easy, fast and cheap, but in your case it is not so much in it, but in the different elements of the overall shrinkage of the system. That system should work the same way, as that is the same perching.
This is the same option when you can not connect under one roof two dissimilar structures. For example, one of wood and the other one made of brick. Foundations and walls between them are not connected. Why? The roof is broken, and the walls are cracked. Wood will never rest. Wooden posts play a role of a not cracking construction and will prop up the roof, "pulling it up and down". I exaggerate, of course, for clarity. And how a cement block can be flexible. You should ask that question to the tillers. The axe (a sharp ax) mounts tiles. There is a suspicion that it will be broken with shifting of the rafters. It is not fixed throughout the ramp, and only the initial series, then simply inserted into the slots. How it will fall on your head if it pops! No, on your roof just flexible.We have learned to draw computer pictures.

[Summer]

It depends on a design of rafters.
Tiles will not be broken as they are too small.
I disagree about the foundation, but about shingles - no.
If the wind can blow CHR, then a half part of houses will stay without roofs and leave the other half houses completely fell apart. Under the posts you need piles.

[bill]

In this case, I will only slap my hands for joy.
I think that I knowingly taught physics at school and 2 semesters of study of the strength of materials in the MISI, therefore I will try to explain how works the Pythagorean theorem in this case.
In the course of a two-story log house shrinkage, a value of the lower leg = a height of the roof is reduced by 5-12 cm, but a hypotenuse = a rafter will remain unchanged. A change of the angle can be ignored , then a larger leg = the distance from a log house to the reception will increase. Voi-la! By the way, what is the program, besides rafters, usually used to calculate the load on the roof?

[constructor]

Particularly, the attention attracted by that part of the roof which is right to the gable. It turns out that the entire piece with a pediment removal keeps on one or two rafters. Oh, and it makes worth such places and even with CHR. Plus, rafters slide on the main slope, the insulation core breaks. To lay such roof with a load will be dangerous with incorrigible slopes. Do you think these slopes are a panacea? As the same. This is not a gable sauna 3 x 4. The most opposite, that on large spans not only the foundation, but the walls themselves shrink differently. A non-uniform drawdown is not compensated. When there was problem around, I just put the screw joints under a point of support rafters. Owner was explained at once every year it is necessary to tighten up, if it is hard to turn, you should jack a little bit.
You want me to come twist - no question. I will choose a day with a team and a gasoline it will cost about seven thousand rubles. But to put joints and then disassemble it in order to twist is a pain in the rear! A large canopy on posts is simple.
Do this canopy under the main roof, which will see the eaves 20-30 cm, as an option, you can fix rafters on the beam of the pillars. An important point has been already said, the main roof should be construct in four years, not before. You can’t cover immediately, the risk is great. You're going out there and other earthen landscape stuff to do. You will hear a wonderful advice - place on the roof tiles and a stone. A shrinkage will be good. 10 tons at the time. 10 tons are the weight of 200 sq. m CHR. During 4 years it will influence to your house, that you will not worry about the further shrinkage. Once the game “fall-spring”, “summer-winter”, “wet-dry”, and it is not so big, if the log house is not from the tree. Let it work the heating. The frame house will shrink and then you will make roofing.

[buldozer]

If a hypotenuse can be ignored, why then use the sliding roof timbers in a wooden construction? It is precisely because we can ignore this value? It is therefore not recommended to do once a normal roof in the wooden houses, and first, under the roofing material? 5 - 12 cm of shrinkage do not dream about! But for 7 centimeters per meter you can count. Your attention, please, instead of your scepticism. I will tell you about refinements. The most sloppy is on the roof ridge between the timbers and a precipitous slinging.
Rafters length remains constant, and the lumber gable wall shrinks, i.e. the length of the pediment (a triangle) is reduced (in terms of the geometry , the height of a triangle decreases) and you can not ignore these centimeters as in a geometry, i.e the ridge beam will shrink together with gables and rafters will bend between two rigid points. This "error" will be visible to the naked eye. Anyone who know something in a wooden building will confirm my words. What then will happen to the tiles and how it will continue to stay in their slots. And then you will tell us. I had to watch it on the roof with shingles.
When you put (sliding) rafters on the corners, then it is possible to release them, that is, to remove the excess length after the shrinkage of gables. An excess length naturally comes out beyond the roof, changing the calculated distance between the roof and pillars to increase. In this case, the pillars remain in place and their height, in contrast to the height of the building does not change. A log cabin in the meantime continues to shrink and not one year. Where to leave posts, if they are rigidly fastened to the roof and how much they will be above the house as a result?
That's the story with the geometry. We love to criticize not even pondering the topic. Read the topic from beginning to end, before evaluating. And for the coolest theorists there is an additional task. Under the previous inputs, the behavior of a pre-existing foundation or any other house with a seating and rigid struts. A prof tip what happens if you combine under one roof a timber and a brick house.

[bill]

Now, for the winter I will just close the roof with a roofing material, in addition we will close with the tiles in the spring. In 2-3 years after the shrinking we should make a good roof? During this time I process the inside and outside of the timber house, and do communications. But it is not necessary to handle a frame house. Do not break a natural drying process. You will spoil everything.
Give it safely to dry. So, who noticed there is shown a great example of the Russian classical method of wood construction: when the ends of logs were painted over to reduce the "vapors" through them. As a consequence, there is the uniformity of a total shrinkage in general, a reduction of number of longitudinal cracks, etc. That's the question I just well versed, but the subject will not be distracted by the formation of cracks. Especially because I have a frame house of a larch. So, there was a great solution to split the roof. The main roof over the log cabins, an additional one (below) over the terrace. For more information - supports are (projections) at a vertical column are linked to the main foundation fittings - 12 - 16 mm. The whole foundation is on the height 25-40 cm = a sand + a gravel after rammers. And a drainage along the perimeter.