What type of wood and how thick for walls and the roof?

[21hens-incharge]

If roofing membrane+shingles will be added, do they need to have the OSB underneath? or can it be something thin and light like MDF? or HW cloth? sorry if this is a stupid question.

There has to be wood underneath to have something to nail to.
OSB is bare minimum. Plywood would be preferred. Roofing nails are a ring shank nail which has ridges on the sides of it to help prevent pull out as opposed to a smooth shank nail.

 

[Ted Brown]

If roofing membrane+shingles will be added, do they need to have the OSB underneath? or can it be something thin and light like MDF? or HW cloth? sorry if this is a stupid question.

Never a stupid question!!

MDF does not stand up to moisture, bad choice when edges are exposed..

You need a solid base to attach the membrane and shingles to. HW cloth does not provide that.

There are roofing sheets that are a rough finish plywood but more expensive than OSB.

Some would argue that the membrane is not necessary but an extra layer of waterproof material is well worth the cost of a 4' roll.

 

[SarahGfa]

Never a stupid question!!

MDF does not stand up to moisture, bad choice when edges are exposed..

You need a solid base to attach the membrane and shingles to. HW cloth does not provide that.

There are roofing sheets that are a rough finish plywood but more expensive than OSB.

Some would argue that the membrane is not necessary but an extra layer of waterproof material is well worth the cost of a 4' roll.

Thank you, that makes sense. I was thinking of the prefab coops that have very thin roofs. I guess the asphalt roof is glued onto the thin wood.

 

[Ted Brown]

The "shingles" in the pictures you included is rolls of a base material with small crushed stones applied via "tar" or glue.

Where that is used in my location it is often referred to as "ice & water" membrane; usually goes underneath shingles or metal sheets. Waterproofing.

Guessing that the use of it per above is a cost cutting step.