Cladding Exterior Bay Window

[CarolinaNomad]

One of my next projects will be to clad the exterior Bay Window with Exterior MDF.  But I'm having no luck in finding the correct way to install the exterior MDF online.  I imagine it's installed similar to hardy board, where you install a 1/2" cedar strapping over the tyvek and then install the mdf.  Also, I've noticed other houses installed the stone or brick work first before installing the MDF.  Any help would be appreciated.

Jeff

 

[peter halle]

When you say exterior MDF, are you referring to sheets or something else?

Peter

 

[CarolinaNomad]

1/2" 4x8 sheets

 

[tiralie]

I would suggest either Extira or Duraboard PW. which is a pvc board with wood fiber. A lot of guys are using it for non-structural trim work such as exterior cladding windows, posts and columns etc . It sands well and paints well.
Extira is used on a lot on soffits and fascia of the new builds in the neighborhood.  Here is the installation guidlines

Both are available at Brenlo.

Because these are not pure PVC panels, I nail and screw as I would with MDO.

I haven't worked with water resistant MDF as it really is rated as "water resistant" not water proof.

Hope that helps.
Tim

 

[CarolinaNomad]

The Extira is the same material I read about this past weekend.  But their website was down when posted.

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This is what I'm building.  Basically wainscotting around the bay window with the extira, but my question is do you fasten the extira directly to the tyvek (house wrap) or place a 1/2" cedar strapping to provide a 1/2" air gap between the house wrap and the extira?

Also, it appears in the photo they installed the brick first and then the exterior mdf against the brick.  But I think it makes sense to install the mdf on the sides before the brick.  Does it matter which order?  Has anyone installed the mdf before the brick?

Jeff

 

[tiralie]

but my question is do you fasten the extira directly to the tyvek (house wrap) or place a 1/2" cedar strapping to provide a 1/2" air gap between the house wrap and the extira?

If I could I would. Trapped moisture between the house wrap and the the underside of the Extira will not be good long term.

Also, it appears in the photo they installed the brick first and then the exterior mdf against the brick.  But I think it makes sense to install the mdf on the sides before the brick.  Does it matter which order?  Has anyone installed the mdf before the brick?

Jeff:
I have always seen the brick/Stone etc. applied and then the trim. Since I don't work on new builds, I am always installing after the fact. Also, the directions for Extira do state "As with all wood products, Extira panels should not come in direct contact with masonry or concrete."

Tim

 

[peter halle]

I would use an airspace.  And instead of actually installing the sides before the brick I would be installing a temporary "form" at the bay / house intersection for the masons to lay the brick to.  Then when you go to install your work you remove it and depending on the manufacturer's instructions install it by sliding it into place past the face of the brick or just shy of the brick and then using an appropriate sealant at that joint.  If you do this make sure that you do put strapping in the area where the brick will cover, but place strapping just outside of where the brick will intersect your future work, and nail your temp form to that strap.  You don't want to fasten your temp work so that it is a bear to get loose so that you can install your final stuff.

Your form boards should be the thickness of your strapping as well as your material plus a smidgen (use shims for the smidgens) to allow for some separate of materials.  Personally I would also be flashing those intersections so that there would not be a reliance on the house wrap. 

Hope that this makes sense.

Peter