Installing 2 Vinyl windows with no nail flange in a 6″ opening depth
I’m turning our sunroom into a finished space. The current slider windows are 2 be replaced by 2 vinyl single hung units (73″ x 52″); each unit has a 2 single hungs and a vinyl joint between each to make it a solid unit.
The current sill is sloped 2×8. Based on my recommendations and manufactures install is to shim sill at 24″ and jambs at 16″ (only fastening the jambs).
They say if > 65″ wide consider fastening through the still; but from the advice I’ve been given from contractor and rona is to not fasten on the sill as it could compromise drainage.
My plan was to trim down the 2×8″ sill and make it flush with exterior 1/4″ sheathing and bring the house wrap overlapping the inner opening and install a self adhesive flashing over the sill jambs and header.
One recommendation I has was to use a j-mould over the sill. But I think self adhesive flashing would be better. If I go with self adhesive, what would be the best trim options to use? Fiber-cement siding is to go over the exterior.
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Also, these are a vinyl-built windows. They recommend installing a drip cap at the header at least 2" up behind the building wrap.
Mike,
Your description and questions aren't clear.
For example, what is "the current sill"? Is that a finish sill from an existing window or a rough sill that is part of the rough opening?
If you have never flashed a rough opening before, I hope that you have searched the GBA site for information on the issue. There are many ways to make mistakes with this job.
Hi Martin.
The sill is existing sloped sill is a true 2x8" that is apart of the rough opening.
A part or apart... Flash the opening.
Fibercement siding trim choices are many, fibercement trim, PVC board stock, preprimed fingerjoint western cedar. Visit your supplier for options and a chat.
Mike,
You need a sill pan on top of the rough sill -- not housewrap.
The sill pan can be a manufactured sill pan or a site-built sill pan. Most site-built sill pans are made with peel-and-stick rubberized asphalt flashing. The site-built sill pan needs to be sloped or else it needs an interior dam to prevent water from entering the house on the interior side.
More information:
Pan Flashing Choices for Windows and Doors
Flashing the Jambs on Flanged Windows
Flanged Window Video Series
Hi Martin & AJ,
I'll go to store and check out what options are available. The peel-and-stick option does seem the easiest / quickest to install.
Cheers