Prosoco R-Guard Fast Flash

Just what I needed for the job.

Works, but a little spendy. Need to sell a 2, 3, 4 pack for cheaper or something

Great stuff, easy to use and does exactly what it’s supposed to. Make sure you’ve got a sausage gun. Won’t work in a regular caulking gun.

Pretty easy to tool even in cold temps, initial tack very good, sag resistant but self levels a bit (I probably used it where I shouldve used the joint filler in some cases.) Is just nice to work with...when paper towels are readily available to keep the spreading tool and all of ones clothing clean. I cant review the properties I cant test such as breathability etc but itd have to be far better in that regard than the off the shelf caulk type products.

this stuff is better than others I have used just too expensive. if you need to seal a small area this is the product you need.

Prosoco R-Guard Fast Flash (and related Joint & Seam Filler) works as described to seal the gaps between different building materials. Tape and caulk products arent all-purpose as liquid flashing products, where you apply a large bead in bulk, and then spread as needed for the situation. Corners, odd shapes, vertical, horizontal, works equally well inside tight spaces as it does across large flat areas. You can push the liquid flashing into cracks in the same way that caulk is applied, plus you spread it out with a plastic fin or other spreader tool. Cleans up easy with paper towels before it dries. The finished product is a rubberish mastic that provides a permanent barrier to water, air and insects. Cure (drying) time is dependent on humidity. If youre working in a very dry environment (e.g. below 50% humidity), a small amount of water misting with a spray bottle will speed things up. Im in central Texas and find most days that I can spread the joint and seam filler in the morning, and then after lunch apply the fast flash. On especially dry days (humidity below 30%), Ill very lightly mist the substrate before applying the joint and seam filler. A great benefit, rain isnt a worry - you can apply these products and not worry about rain later in the day! The joint and seam filler is pink and reinforced with fibers, designed to fill large gaps between material, goes on very thick and the finished surface isnt as smooth/flat in comparison to the fast flash. Fast flash can be used by itself, or on top of the joint and seam filler. Dark red in color, nearly the same product as the joint and seam filler, but less fiber reinforcement to allow being applied as a thin top-coat that finishes smooth and sexy! Applied successfully at the foundation between concrete and base angle (e.g. sill plate) for metal buildings, workshops, and barndominiums. Works great for commercial and residential construction across a wide variety of materials!

At first you will hate this product. It will feel messy and you will use way to much and think its to expensive. After a couple windows you will get much cleaner with it. The best part to me is how it seals air out. After windows are installed you cant feel a draft whatsoever and this is before you foam the window. Not to mention I know my windows will never leak. Is it expensive yes but the flashing tapes arent cheap either and are a pain and they arent perfect by any means especially if your openings arent great or brand new. You can coat a cardboard box with this then fill with water. It will not leak. Then you can put a screw through the box and it still wont leak. You can see a video of this on YouTube. I can now do a 36x60 window which had extremely large jams at 8.5 inches. Did inside and out around insulation lockouts. This one window took less than 1 tube of this. If your doing a normal window with normal jams you would use alot less. If you are using more you are using to much. It spreads along ways but doesnt feel like it will so it can be easy to use to much. The other product joint and seem filler is awesome as well. Im just a homeowner putting my own windows in and wanted the best product I could find. I also do not believe foam alone stops air drafts well as other windows I have without this leak air like a siv around the interior casing and I had to caulk them. No such problem with this product before foam

I use this product a bunch and really like it. It does take a while to learn just how to work with it so it is perfect. It does take longer to use than sticky tapes, but I feel the quality is much better. I wish they had different options when ordering on Amazon such as quantity amounts to help save on shipping. For example, order in increments of 5.

Used on two new window frames and gave up. The material is sticky and hard to spread. One sausage might only be good for one and a half regular sized window. I ended up using good old window frame flashing tapes again.

Applied product to pored concrete wall and sill plate. 1 1/2 inches on each to seal the sill plate and stop bug and air/water infiltration. Went on smoothly. Glad i saw this on the Build channel.