Basement window replacement questions (flashing & wood buck fasteners)
![](https://secure.gravatar.com/avatar/6b0f38ca4c924cfc493b3a70ca53a18f?s=52&d=https%3A%2F%2Fimages.greenbuildingadvisor.com%2Fapp%2Favatars%2F200x200%2Fp.png&r=g)
I’m getting ready to replace an old basement window in my 1960’s colonial with a new egress vinyl window. The foundation is 10″ poured concrete and I’m going to install 2×10 bucks around the opening. I’m planning to use sill gasket between the concrete and wood as a capillary break and a layer of caulking to prevent any potential insects from squeaking through.
For my flashing I’m going to use Zip Liquid Flash for everything, no tape. My question is should I liquid flash the concrete opening prior to installing the wood bucks, or just liquid flash everything after the bucks are installed?
Also I’m planning to use 3″ RAMSET nails for securing the bucks to the concrete. I usually use RAMSET for shooting plates to the concrete floor but wanted to check if using them to install the two vertical bucks is OK or do I need to use tapcons?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb1.png)
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb2.png)
Replies
aberrant,
Rather than a full depth 2"x10" buck, consider using a 2"x3" or 2"x4" and covering the rest of the opening with 1 1/2" foam board. If you sheath the buck and foam with plywood, and it will minimize thermal bridging and condensation.
I would liquid flash once the bucks are in.
I've had mixed success ramsetting into old concrete. If it were me I'd use GRK Caliburn screws.
Thanks Malcolm, I like the idea of using the foam board for the non structural part of the buck. This will tie in with the rest of the 1 1/2" foam board I used on the walls.
I had good luck with the ramset on the sole plates but I will look into the GRK's, unfortunately looks like they don't stock them at the HD near me.
aberrant,
Try a test shot. The ramset may be fine.
I prefer the GRKs over Tapcons. They are much beefier, so less likely to break or strip.
Seems likely if the old windows are steel the frames will likely be imbedded in the concrete you will likely need to cut the steel before you can remove each part. Sawzall with extra metal cutting blades and an angle grinder will come in handy. The wooden bucks may not be necessary most basement windows are the same sizes and replacements are often a stock item.
Tapcon screws are generally the fastener of choice with some caulking.
The bucks will shrink the already small opening and put you into a special order window.
Walta
Thanks Walta, these windows are full height, not the typicaly steel hopper windows.
However, I do have 2 steel hopper windows that I will be replacing after I install this egress window. My plan for those was to fully liquid flash the steel frame and install directly into the steel frame and anchor with concrete screws. I'll have to remove the lips that the existing sash seals on because the common replacement sizes are too large to fit my opening... figures.