Advice for the realization of an extension of my house

[bidouille23]

Hello ,

go here: http://boisphile.over-blog.com/tag/la%2 ... 20-%20mob/

to use without moderation;) .... even abuse ...

1 / - I hesitate in choosing the wood cladding between red-cedar and Douglas fir. What do you recommend for the region? Is the durability of the cheaper Douglas fir satisfactory?


personally I would take the one that grows near my home (and at home in Brittany we take Douglas-fir without sapwood;)) and it lasts ...

the important point is that there is no sapwood. and respect the siding start height .... app 20 cm minimum ...


2 / - I hesitate between "micro-piles" or "plots and longreens" foundations. What do you recommend ? Do I have to do a soil study?


the big advantage of a MOB is that it is light .... But you still need to know a minimum loa nature of the soil ... when you dig at home it is soft or it is pebble ? without going to the actual soil study. a good blow of mini-excavator on 50 cm deep will already give you a good idea (50 cm below the level of topsoil will already be enough)


3- the part where the extension will be located is currently wet. Do I have to make an insulating floor and put peripheral drains to the concrete slab?

I don't know do you want to have a living room or a humid cellar?
Personal it is compulsory peripheral drain especially if the ground is wet, and insulated the slab is part of the general insulation of the house (you will see insulating a slab afterwards it's not cool;)).

personal: mob extension on concrete sole in concrete block, and non-load-bearing insulating slab with expanded clay in place of gravel. and peripheral drain (that's for me)


4- I want to make a low slope roof (or terrace roof not accessible). Does this choice seem judicious? How to make the waterproofing junction with the slope of the roof of my garage including Roman mechanical tiles?

Personally the slopes no one for me is a poop nest ..... or rather a source above my head when it's puddles;) ...

what is your garage what direction the slope of the future roof?

5 / - should I make a wooden frame wall (and expansion joint) adjacent to the north wall of my house or can I get rid of it?

??? a drawing can be ??

6 / - what is the recommended thickness of the insulation thickness to obtain R> 3.7 m².KW? I hesitate between 3 types of insulation: HD rock wool, ISONAT, cellulose wadding. Do you have any recommendations on these insulators and the implementation of the walls?

R = e / lambda of the insulation with e = thickness of the insulation in m

reread jp olivia again i think.

personal cellulose wadding, because density, speed efficiency, respect for nature because from recycling .... and now the price is much better ....


7 / - concerning the heating solution to be implemented, I hesitate between 3 solutions: installation of 2 inertial electric radiators, extension of my gas central heating network by adding 2 radiators or installation of a pellet stove in my current house. A duct currently exists near a cross wall and I should create a network returning the heat to the wood extension. What choice do you recommend?

.... if you insulate thoroughly and you control the air leakage well you can quite get a passive extension, so with little heating demand. personally I would lean towards the pellet solution (just by telling myself that the future of gas is to increase) ...

8 / - I will have to set up a patio to keep the natural light on the 2 windows on the north side of my house. Do you have any advice / suggestions on this solution?

yes a refat board photos with the geographical location marked above , story that we understand what you are talking about;) .... a plus

[bidouille23]

question:


how are you building your house? supporting slab or sole? here will give you lots of clues when the nature of your soil;), and if its door a concrete block it will quietly carry a wooden house ...

[Coati84]

Hi,

After a period of silence, I come back to the forum with news.

Thank you Bidouille23: here is what I found on the foundations of my house. The foundations of the existing house are:
Concrete belt around the house (this concrete belt is filled with large pebbles and includes some kind of terracotta duct allowing moisture to be evacuated)
• Peripheral walls:
- hollow bricks with a thickness of 28 cm (dimensions: 40 x 28 x 15 to 5 cells)
- exterior plaster with a total thickness of 1.5 cm on brick (1 gobetti and a second float layer 1/3 cement 250/315 and 2/3 lime 30/60)
• Dry stone hedgehog 15 cm thick with 1 drain every 150 cm connected to the ventilation
• Concrete form on hedgehog: 10 cm thick with 800 liters of gravel for 400 liters of river sand
• 2 cm thick cement screed

I really know nothing about foundation. With the elements reported above, can you direct me towards the 2 solutions that I envisage for the foundations of the wooden extension?
a) "continuous sole with ventilated vacuum of 60 cm"
b) "concrete blocks (80 to 100 cm) and stringers"
Finally, is your solution "continuous concrete block sole with non-load-bearing insulating slab with expanded clay and peripheral drain" duplicable for the foundations of my wood extension?
Wishing to entrust a mason with the realization of these foundations, what is the budget to consider for the foundations / insulating slab for a footprint of 50 m²? What is the additional cost linked to a crawl space 60 cm high on a surface of 50 m²?

I currently have a sewage system from my house that goes 30 cm underground at the site of the extension. From a technical and economic point of view, should I rather consider the "crawl space" solution under the slab or rather a deviation of this evacuation network around the wood extension?

I would prefer a priori the roof solution in steel tank (3% slope) with aluminum cover. What are the best sealing solutions? How to manage the connection with the north wall of the existing house?

I am in the process of finalizing the sketch of my wooden extension located to the north of my house which will have a floor area of ​​approximately 39 - 40 m². I enclose the plans and the associated sections. What do you think ? Do you have technical and / or aesthetic suggestions?

Thank you for your always precious help & see you later.

[Coati84]

Hi,

I advanced on the studies and intends to deposit my building permit by the end of the month having made the choice of future foundations.

Finally, here is my choice concerning the foundations / slab of my future wood extension:
- Shrinking base w = 30 cm xh = 40 cm around the perimeter / sills / brackets / stiffeners / welded mesh / peripheral drains
- Ventilated vacuum: 4 rows of concrete block 20 x 20 x 50 on this scrap steel base plate
- Beam floor with insulating interjoists
- Concrete compression slab th. 7 cm with 3 cm expansion joint opposite the current house.

What do you think ?

Since the area is not clayey (discussion with the technical services of the town hall), I do not intend to do a soil study or concrete study. Do I take a risk? Is the section of the scrap base plate (l = 30 cm xh = 40 cm) reasonable to then receive the different rows of concrete blocks / the floor / the wooden frame?
The section of the scrap reinforced base (l = 30 cm xh = 40 cm) of the future wooden extension is less than the section of the sole of the existing house (w = 50 cm xh = 70 cm): due to the mass very high of the concrete block vis-à-vis the OSB structures, this value seems adequate to me. What do you think ? In conclusion, I prefer to discuss it with a serious mason than to carry out studies of soil and concrete which will cost me approximately 2 € for undoubtedly not much: your opinion?

Thank you for your advice & good evening.