Eco House roof

[sandyocon]

I'm building an eco house buried into a bank, dimensions 6.7m deep x 5m wide. The roof is going to be covered over in soil and planted with wild flowers. How would you suggest I do the roof so it can bear the weight of the soil? See drawing attached.

 

[SlideRuleEra]

The best material for use underground is concrete, either prestressed or reinforced cast-in-place, but there is more...

The soil on the concrete roof plus the roof itself will have to be supported by the walls. So, the walls have to capable of carrying heavy loads. That leads to...

The soil on the roof, the roof itself, and the walls have to be supported by a strong foundation that is suitable. Then...

The soil on the roof, the roof itself, the walls, and the foundation need to bear on soil that will not settle, and...

The roof, the walls and the floor need to be waterproofed so that the interior of the house is livable...

To minimize water problems, the soil around and above the roof should be graded for good drainage...

Bottom line - There is much to consider and address. The best way to do that is have structural, civil, and geotechnical engineers design the project together.

http://www.SlideRuleEra.net

 

[LittleInch]

Agree with SRE here. Soil and a presumably flat roof (nothing was attached) can be a huge load to sustain and permanently wet / regular personal access, maybe with machines has a whole host of issues.

So what is suggested is that you get it designed by a competent structural engineer who will certify this to everyone's satisfaction, call off the correct materials and construction details and your eco house will then remain crack free and water tight for decades to come.

How come only the roof is an issue? Who has been designing the rest of the house?

If half of this is already built then you have a big problem.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MegaStructures]

How come only the roof is an issue? Who has been designing the rest of the house?

In my experience most non-engineers don't realize soil creates a lateral pressure. That's my guess as to why the roof is the only issue brought up here.

As others have said very high loads associated with a "live roof" and lot's of weatherproofing considerations. As far as weatherproofing is concerned I seem to recall there being some companies that sell pre-packaged solutions, at least for roofs (not sure about walls. The structure will need to be designed by a skilled structural engineer, I would be equally concerned with the lateral pressure on the walls, as the huge load on the roof.

How deep will the roof be buried in soil? Surely it is not 6.7m of soil covering. That would be a bad idea.

 

[dik]

Waterproofing and drainage is critical... might want to include a 2% slope to your roof... one side to the other or from ridge to eave. YOu can even have a clay seal over your membrane and insulation, with topsoil over.

Dik

 

[r13]

You need to retain the soil on your roof with steady/mild slope, and surface protection, either by vegetation or erosion protection materials, or both. Also, make sure the soil is free draining with a good roof drainage plan. On top of structural engineer, you might have to engage a geotechnical engineer.

 

[BUGGAR]

Maybe consider a corrugated arch type design. There are standard highway designs for these.