Doors and Windows - Replacing windows - concrete block home

If anyone has any comments about this situation, it would be greatly appreciated.

We are going to be replacing our circa 1978 single paned aluminum windows with double paned vinyl. We are in Florida and the home is concrete block construction with no interior or exterior trim molding on the existing windows, just about 4 inches deep of drywall inside. A few months ago we removed the kitchen window to check out the framing and see what we needed to do. It just unscrewed and popped out of the opening, no problem ( as there was no exterior trim to remove). The original windows are thin, and therefore, the framing consists of a thin (maybe about 1 1/2 inches wide) buck strip stapled to the block. As I said before, the interior is drywall, and it looks like that is just glued to the block. When you put the new window in
(we were trying an american craftsman at the time, but didn't like it), it's alot thicker than the old, so the side frame of the window comes in and covers part of the drywall. The screw holes will be set inside past the wood buck strip, so one would be screwing thru the drywall and then into the block instead of the wood. My question is: is this method OK (using Tapcon screws), or is it better to remove the old strip and some drywall, and reframe the whole opening? (I really don't want to do this, but will try if it is necessary).

Also, the interior window sill is one of those marble strip thingies. Can the bottom of the new window just rest on this sill, or should it be shimmed up a little? A good bit of the depth of the sill will be lost due to the thickness of a new window, but I'm not sure how involved replacing it would be. It looks like it is cemented right to the concrete block.

Thanks.

My question is: is this method OK (using Tapcon screws), or is it better to remove the old strip and some drywall, and reframe the whole opening? (I really don't want to do this, but will try if it is necessary).

You can screw through the window and the drywall with the tapcon screws- just make sure they go into 1" of cement. I've found that 1/4" tapcons work best. But I'm not sure what doing that will do to the outside. I assume you will have to anchor a treated wood blind stop around the outside, and perhaps wrap it with aluminum trim coil? Additionally, there will be a gap at the sill, and unless your new window comes with a snap in sill expander, you would also have a gap at the bottom to fill. (putting a stop on the bottom is usually a bad idea, since it can trap water.)

Also, the interior window sill is one of those marble strip thingies. Can the bottom of the new window just rest on this sill, or should it be shimmed up a little? A good bit of the depth of the sill will be lost due to the thickness of a new window, but I'm not sure how involved replacing it would be. It looks like it is cemented right to the concrete block.

Sure, it can rest on the marble, as long as you never want to change it. The only problem I see with this sort of installation is how you are going to trim the edge of the new window, since it will have a small gap around it. Sometimes vinyl windows will also have a 1/8" wide groove around edge of the window (which is usually covered by wood stops), so just caulk would not be enough to cover. (unless you like 3/8" wide beads)

If you wanted to think about another way to install your windows, some brands of vinyl windows can be ordered with an optional drywall receptor. It snaps into the groove I mentioned earlier. What you could do is remove the drywall jamb completely, install a window (with drywall receptors) in the cement opening that is 1/4" smaller than the opening, then insert new drywall right into the receptor, glue and shim it so your corners are square and then replaster new corner bead all the way around the window. If you went this way, you might want to remove the marble sill, drywall all 4 sides, then if you think it needs something additional, put it on later. (a marble or oak sill on top of the finished drywall opening). The outside edge of the window would only need a bead of polyurethane caulking.

Everything XSleeper said will work. Many times (mainly in older apartment complexes) they have the same situation concrete block exterior walls, aluminum windows that drywall butts up to. I've always measured so the new window will sit on top of the drywall (so the new window is back in towrds the interior wall since typicall the old windows were only 2 1/2" or so deep and the new windows are usually 3 1/4". Before I install the new vinyl window I'll rip some treated 1x's to buck out the rest of the opening so after new window is installed I'll have something to nail the outside stop to for capping after i'm done.

As far as the inside, there have been many cases where I've had to nail the inside stop 1/4 round/cove molding whatever, right into the actual vinyl window frame itself. If you've ever tried to pull a nail (mainly brad nails) from the vinyl window frame you know they hold extremely well. Most times you will bust up the stop and the nails/brads will not budge a bit.

Not a big deal at all, but doing it so it looks right is where experience comes into play-as well as having the right tools for the job:) :thumbup:

I certainly appreciate you taking the time to answer my post. If you were still around maybe I could clarify a couple of things. Your reply scared me a little bit, just because I am not familiar with some of the terminology :eek:

This will be my first window install, but we are generally pretty handy (I've done a little drywall, and some tiling, and basic home repairs, etc.). When we took out the old window, it just looked like, OK, you pop out the old window, pop in a new one, screw it in, caulk it, and your ready to go. You spoke of window stops and blind stops. I don't think my existing window has any of those (there is no interior window trim) unless that is the wood framing in the concrete block, that I called a buck strip. The new window we were looking at is similar to the existing in that it has a 1/2 inch flange all around the exterior of the window. I believe that we would just caulk this flange and place the window in the opening and the flange rests against the buck strips (or wood stops? :confused: ). This keeps the window from going into the opening any further.

But I'm not sure what doing that will do to the outside. I assume you will have to anchor a treated wood blind stop around the outside, and perhaps wrap it with aluminum trim coil? Additionally, there will be a gap at the sill, and unless your new window comes with a snap in sill expander, you would also have a gap at the bottom to fill. (putting a stop on the bottom is usually a bad idea, since it can trap water.)

I don't think what I'm doing affects the outside at all, the screws are going into the side window frame (jamb?) and into the block window opening perpendicular. They will not encroach on the outside at all. I'm not sure why there will be a gap at the sill, if the existing window doesn't have a gap and the new ones look like they are constructed the same way, (with a flange around the outside) they are just alot thicker so it sets deeper into the window opening and on top of the interior marble stool (I called this a sill in my earlier post, maybe that was incorrect). Not sure why we would need the aluminum trim coil, there is no exterior trim on the windows, it's just a window stuck in a concrete block opening. I tried to look up a sill expander, but I'm not sure I have an idea of what that is.

I see what you are saying about the potential for large caulk lines on the inside of the window. (I had wondered about that before myself) The drywall receptor thing is something to think about, althought I'm not sure I want to re drywall the opening in every window in the house. It seems like I read about some vinyl trim that you could get to snap into the same window groove the receptors would snap into. This may cover up any larger gaps or caulk beads. I may try that first, and then if it looks like crap, I could try your method. (I guess that if I wanted to have a real nice interior look, with trim moldings, etc. that I would definately have to remove the drywall jamb and redo the opening with proper wood framing)

The marble sill (stool) I talked about may have to be removed with a sledgehammer. Perhaps if I wanted a larger stool, I could get wood ones and install it over the marble (I'm just thinking crazy thoughts here :thinker: ) That would also serve the purpose of covering any ugly seam between the bottom of the window and the marble stool.

Well, lots to think about here.
Peace.

WOW, LOL, times like this are when there were articles on line that covered every install imaginable, but it'd take half the internet space since they vary literally form house to house and each case presents it's own little problems.

If your 1/2" flange your talking about is a nailing fin? this could prove to be problematice in the overall plan of easy of installation and finishing inside and out. So, first and foremost, are you installing new construct windows or replacment windows, this will dicate which route to go with the installation directions.

I'll base this off replacement windows (they WILL NOT have any nailing fin around the perimeter of the window) First you will take a measurement from the finished drywall on the left jamb to the finished drywall of the right jamb, then you will take a measruement from the top of the marble stool to the finished drywall on the top of your opening. Take these mearuements so it's tight, then SUBTRACT 1/2" off the side measurements and 1/4" off the top to bottom measruement.
Ex: side to side measures 30" your window will need to be 29.5" wide (29 1/2")
top to bottom measures 40" your window will need to be 39.75" (39 3/4")

This will allow you to install your new window to sit inside of your finished opening. You will screw it in to hold it in place. Insulate around the window and install the inside stop. Inside stop will be wood of your choice that will cover the gap between the opening and window frame so you cant see the insulation and give a finished apperance.

As far as the opening, once you remove the old window there will be a step from the finished drywall/marble to the cement block opening. You want to install some kind of treated lumber to fill that step so the wood will be flush with the finished opening (your drywall/marble)-or below flush just a wee bit.

Once your window frame is bucked out with this treated lumber, you will install your new replacement window. After it's screwed into place you will see that gap around both sides and top of the window from the outside looking in-this is where insulation will be stuffed to prevent air infiltration. Now you need to cover the gap on the outside with some kind of wood so you dont see the gap/insulation. This is called the outside stop. You can use treated wood and paint everything when your done, clear pine and paint it when your done, etc... or like we mentioned cap it all with aluminum coil stock for a maintenace free exterior.

This inside/outside stop are what REALLY hold your new window in place since it sandwiches the window between to wood nailers so to speak.

In your particular case, I would not use a new construct window since this is just not the right application that style was designed for. Replacement windows are perfect for your application.

The sill expander on the "good to beest windows" are a peice of vinyl that F shaped. The top of the F will nail directly into the channel at the bottom of the window-you will have to cut it to length so it fills the void between the bottom of the window and top of the sill. Many of the older versions of replacement windows just come with a small L shaped peice that you nail into place on the sill first, install some insulation and tip the window into that L strip. MANY sills are cut on steeper than 15* angles so more often than not those cheesy little L shaped expanders will not even come close to touching the bottom of the window once you install it, then you have more problems to solve. It may just be me, but that's one the first things I look at on a window design to see how "fresh that companies design is" If thier stil lusing that junky little L shaped expander, they often still use that ugly looking H panel that sits on top of the window as well to fill a gap if the window is miss measured. They were neat 15-20yrs ago when replacment windows first hit the scene, but that design is dated and IMO, if the company has not even moved forward in design, lord only knows how cryst the acutal window will be since they obviously have'nt kept up with the times:)