Replacement Window - Gap at top

Acre · 12-10-2009, 11:34 AM

I had installed a vinyl Silverline window and it came with a 'header' piece that I put over the top of the unit and it made for a tight fit.
Now I am installing a Pella 850 wood window. There is a 1/2 inch gap at the top and they do not provide any kind of 'header' piece to put over the top. Does anyone know what I do to fill this gap (other than the Pella recommended install technique of a bead of foam.

jaros bros. · 12-10-2009, 05:56 PM

As long as it is against the stops you should be okay. You might want to shim it to split the difference. The expanders are only used for large gaps so you are okay. Yes, low expanding foam to seal it up good.

Just Bill · 12-11-2009, 07:20 AM

Head expanders always come with the replacement windows I install, but I NEVER use Pella. And 1/2" should have an expander, filled with fiberglass insulation. This allows it to compress for inserting the window and expand to hold the expander to the top.

Acre · 12-11-2009, 07:31 AM

Well I guess I will use shims on either end of the bottom to boost it up a bit. The Pella instructions say to do that if the sill is not level so I guess it will not sag in the middle if I do that. Like I said I only have experience with one other window and the cap certainly made it easy. It seems like everything I read says leave 1/2 inch on the vertical. I would really like to know what they expect people to do if a 1/2 inch gap is a given when installing their windows. I would think Lowes forgot to send me the caps (they forgot to deliver the screens and grids) but their is no mention of end caps in the directions.
OK. Thanks all.

Just Bill · 12-11-2009, 10:37 AM

When I order windows, I supply the opening size, which gives me a make size of /14" less on either side. If the existing window frames were properly measured, the new windows would fit better. Shims may not work. The entire bottom needs to be supported, so you will need one shim the width of the window.

Acre · 12-11-2009, 04:56 PM

Went to see the Lowes guy that sold me the window. He said I should put 3 strips of 1/4 inch lattice on the sill to cover the entire sill. The width of the window is a problem also, as it's 1/2 inch short. The Pella window barely touches the exterior stops on the side of the window.
I think 1/2 inch short on the width and 1/2 inch short on the lenght is not the correct size to have sold me but I think I'm stuck with them. I notice that on the Pella site they say to measure your window and bring it to a dealer to have him determine your correct size. In other words they don't say 'measure your window and then subtract X from the measurements'. They don't give you a rule of thumb.

jaros bros. · 12-11-2009, 05:11 PM

Perhaps that is the reason the window doesn't fit? You have two options when ordering the windows and you need to specify and make sure the salesman know what dimensions you are giving him. You can either state the size you need or state the size of the actual opening. If you state the size of the actual opening, the company will automatically downsize to what they recommend.
I prefer to tell them the actual size and downsize it myself because I can tell if the opening is out of square and make the adjustments I need myself.
It sounds like you gave them the size for the window itself and they took it as the opening size and downsized it even more. Your salesman should have explained this to you, especially since you are a DIYer. You could always take it back and get a new one ordered or apply some bigger stops and use shims.

Acre · 12-11-2009, 10:07 PM

Thanks. I think I will do as you say and make the stops bigger. I think I will just glue and nail a strip of wood onto the stops. I'm 63 years old. I hope this contraption I am putting together outlasts me.