Important plumbing issues

I am remodeling my kitchen which is on the first floor. Right above the kitchen is full bath. All second floor bath fixtures batt outside wall. As 2 X 8 joist run perpendicular to that outside wall and the wall is framed with 2 X 4 all second floor fixtures drains are not hidden inside plumbing wall but instead ugly hang a foot or so from the wall inside space above the kitchen cabinets. I do not think the venting is correct. Curently drains from bath tub, toilet and lavatory come almost to the same point in 3" drain vent stack (they are not exactly in the same point, may be a foor apart) and 3" vent continues through the rough. Is it correct venting? I thought all individual vents for each fixture should go up and then connect to main vent stack 6" above flooding level of higherst fixture, it means in the artic. First, I need to do something to hide all drains as right now they break entire kitchen, I do not want to close space above new kitchen cabinets. What's the best approach to do this? What maximum size of holes can I drill in 2 X 8 joist close to the end? I obviously cannot dril holes for 3" toilet drain but can I drill holes for 1 1/2" or 2" in PVC pipes?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sasha wrote:

In some places, that type of stack venting arrangement IS permitted.
Important point is that the toilet must be the *lowest* fixture discharging into the stack.
I am not the wood framing expert, but there is probably no problem drilling for 1 1/2" pipe near the end of the joist (close to center or near the top).
Jim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I am not sure I understand what ou mean "lowest fixture discharging into drain". I have bath tub, lavatory and toilet. I do not have any vent issues, like sucking water our of toiltet. Regarding drilling holes, 1 1/2" is inside diameter, outside diameter for PVC pipe is about 2".
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sasha wrote:

I was concerned that maybe you were going to re-arrange the way the fixtures connected into the stack. In that case, make sure the toilet does not enter the stack *above* the tub and sink.
If you are not changing it, disregard.
Yes, I know that 1 1/2" pipe is ~ ID.
Jim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.