Is there truly a curbless shower and can it be built with effecting joists?
There is such a thing. As far as affecting the joists, that would depend on the total hight you need to meet up to. The pan will need a n acceptable slope, so the most common practice is to cut away the subfloor where the shower will go, sister 2x4 or 2x6 1 1/2" lower and install 2x6's filling in the cavity. Your shower pan floor should be 5/8 or 3/4 lower now. On the outside of the shower, you will most likely use 3/8 underlay on the outside of the shower for the bathroom floor. Your shower floor should now be 1inch to 1 1/8 deep and should give you an adequate slope to the drain. Most shower pre-fabricated pans are still higher than that. I believe schluter and other companies make a low profile pan to accommodate that height. Otherwise, mix up some dry pack and slope in your shower pan by hand. Hope that helps. Note; in any curbless setting, it's advisable to use a low flow shower head. At least be prepared if the one you are using could push the water out of the shower area with too much pressure.
One option which is effective and cost efficient is to raise the floor around the shower with plywood.
This option only works if 1). Your bathroom is completely demoed and 2). There is still alignment with the flooring outside of the room..
Yes Schluter makes a low profile perimeter shower base/tray called Kerdi Shower TS.
You still need to lower the sub-floor to be flush with your joist tops in the pan/tray area and add a certain amount of plywood thickness to raise the remainder of the bathroom floor depending on the tray you select.
No need to reconfigure your floor joists with this system and helps maintain a minimum build up so as not to affect the transition difference at the doorway
Search the TrustedPros directory and discover the best contractors in your area.Find your home service pro