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I have a set of fixed glass windows on a 1 year old house that leak quite badly (soaked the insulation). This is mostly due to the way they were installed because it relies on caulking as a primary mechanism to make them weather tight. So I wanted to query you all for suggestions as to how best to remedy. The details are below:
The windows are built up out of 4’x6′ insulated glass installed in 2×6 rough framing.
House has 2 rows of 5 of these 4’x6′ windows on one wall, horizontally separated by 1×10 cedar and bordered by 2×4 cedar. The window wells are trimmed in 1×4 cedar on all 4 sides. The 1×4 cedar forms the outside blocks for the glass to keep it in place. The following jpeg picture shows a cross section of the window. In my opinion, this isn’t a very good method of installation.
A polyurethane caulk (Vulkem 116) was used to seal between the 1×4 cedar and glass and to seal the joints between all of the cedar trim. The problem is that the caulk has separated from the glass and is cracking where it was used to seal the trim. It appears that UV exposure has something to do with the caulk cracking. I have stripped the caulk once and reapplied, but this was only a stop gap until I could figure out something permanent.
Anyway, you folks have any ideas? I have a couple things in mind, but my experience here is limited. One thought was to install butyl tape between the trim and glass to both seal and avoid direct glass/wood contact and then caulk that, but that may still not be a permanent solution and doesn’t do anything for the trim joints.
Thanks a bunch!
Steve Wright
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steve...i'm assuming that is a cross section and not a plan view..
the sill must be below the insulated unit.. the insulated unit has to sit on a level glass setting bloc..
the block for that size unit would be hard rubber, about 3/16 thick, 1/2 wide.. and extending past both layers of glass.. it has to bear evenly on the setting block... two for each bottom..if it doesn't .. gravity will help cause premature failure of the seal....
the sill has to slope away from the front face of the unit....
ie: it should look like a commercial unit..
after you have the frame correct, use a good quality caulk and good paint.. you are painting these units , right ?
b but hey, whadda i no ?
*Steve,I have to repair these types of installation an awful lot. You are correct, this is a lousy construction method/process to use. It WILL rot in the future. You can do a temp repair, but that's all you'll get. I have to do one of three things when I do these repairs (depends on the customer and the budget). First method I use is to replace the home made windows with insulated window units. Second method is to repair damaged/rotten wood, reseal everything, then install an awning or other type of cover that will protect the window from direct contact with rain. Wind blown rain still creates a problem, though. Third method is to repair the damaged/rotten wood, then reinstall window using a better method, but still not a perfect remedy. When I reinstall the glass, I use a special sealing tape (from a glass supplier) that will seal the glass from water penetration past the glass. The wood around the glass (on the outside)will still get wet, and eventually rot. The new sill MUST be beveled outward (I prefer a 22.5° angle for this). The new sill, and the new outer trim pieces (in your case, a 1 x 4 cedar board) must be sealed also. Common practice here is to use a 3/4" quarter round trim to hold in the glass. I hate the stuff for this purpose. I use a 1 x 2 CCA treated board here. It can be routed for a better appearnace, if so desired. I use 100% silicone sealant to seal the outside trim boards. Apply liberally BEFORE you set the new trim boards in place. I pre-prime and pre-paint all wood before I install anything. This is not my favorite repair method, but sometimes this is exactly what the customer insists on. Good luckJames DuHamel
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I have a set of fixed glass windows on a 1 year old house that leak quite badly (soaked the insulation). This is mostly due to the way they were installed because it relies on caulking as a primary mechanism to make them weather tight. So I wanted to query you all for suggestions as to how best to remedy. The details are below:
The windows are built up out of 4'x6' insulated glass installed in 2x6 rough framing.
House has 2 rows of 5 of these 4'x6' windows on one wall, horizontally separated by 1x10 cedar and bordered by 2x4 cedar. The window wells are trimmed in 1x4 cedar on all 4 sides. The 1x4 cedar forms the outside blocks for the glass to keep it in place. The following jpeg picture shows a cross section of the window. In my opinion, this isn't a very good method of installation.
A polyurethane caulk (Vulkem 116) was used to seal between the 1x4 cedar and glass and to seal the joints between all of the cedar trim. The problem is that the caulk has separated from the glass and is cracking where it was used to seal the trim. It appears that UV exposure has something to do with the caulk cracking. I have stripped the caulk once and reapplied, but this was only a stop gap until I could figure out something permanent.
Anyway, you folks have any ideas? I have a couple things in mind, but my experience here is limited. One thought was to install butyl tape between the trim and glass to both seal and avoid direct glass/wood contact and then caulk that, but that may still not be a permanent solution and doesn't do anything for the trim joints.
Thanks a bunch!
Steve Wright