Don’t ‘Gimmie’ That Line!

The name/term ‘line’ means a lot of things to a-lot of people. Bottom line. Water line. Line of credit. Line of sight, and on and on. The term has numerous ‘homes’ in the construction business also. The one Pete the Plumber is wary of is: ‘snap line’.
 
Snap lines are thin, strong, woven strands of various fibers that have lots of stretch quality and builders use them in various capacities. When snap lines are strung on ‘batten boards’ governing a building’s foundation shape, if it be a slab foundation type, those strings (lines) are especially nettlesome.
 
At the last step of excavation and form work (both foundation types) just before the phone call for the redi-mix trucks, lies the ‘silent question’: are the lines still true and nobody moved them? The fact is that the strings do get moved on occasion, for a few legitimate reasons, but are always conscientiously put back to true. Another fact: on rare occasions, whether slab or ofg (off the ground) when the plumber arrives to set finish, it can be painfully learnt that your toilet, tub/shower or lav wall is up to maybe four (3 & 5/8ths) inches out of place. Your twelve inch rough toilet bowl; your 5ft. tub or T/S; and/or your lav plumbing is up to four inches from where they want to be. Or better, where you, the plumber, wanted or hoped to find them.
 
This is why the author always disliked slab jobs when he was assigned the job of “stringing the lines”.  When the hopefully (rare occasion) “who done it” event occurs, it’s one, big hick-up for the owner and contractor, and especially a plumber sub. On off the ground construction, the building contractor creates a shell of framing and calls the plumber to come to work. If something “isn’t right” rectifying the situation is greatly less of a problem. In this post PtP will share his expertise in dealing with this most unfortunate situation.
 
Time Out!
 
The author wishes, here, before we get going on-topic, to share a horror story dealing with un-true lines. In his youth, and still an apprentice, he and Tiny (Me and Angie) showed up at a job site where they were soon to go to work. The new house was a “hillside” build. (T’was 100 ft. off the ground on the downhill side.)  The “foundation” was composed of twelve 40 ft. deep “dead men” connected with grade beams. These vertical, steel reinforced dead guys were 24-in. diameter, with anchor bolts ready to accept a prefabbed steel beam support structure.
 
The horror: when the erectors arrived and tried assembling the structure, the bolt holes in the steel frame mounting plates did not match up with the bolts protruding from the dead guys. Talk about a conundrum. ‘Somewhere’ in the lay-out process, a string-line was moved and not replaced to true.
End of story.
 
I was reminded of that discomfort recently when I was walking past a construction site down in the big city: Some plumbers chipping up the slab, in a new-construction, framed-in room of a new development. They were chipping in front of the 4-in. closet stub-up. It was obvious to the observer what and why they were busy there that day. A ‘string line’ had been moved and not replaced or improperly strung to the point of now freezing below slab plumbing in their now improper locations. On slab, it’s a great deal more painful for the plumber having to move the pipes to accommodate re-positioned bottom plates than this feat causes when on off-the-ground foundations.
 
Wild Card
 
If you ever find yourself in this predicament, especially in slab, and the fixture involved is a closet, there is only one specially designed fitting that can save the day, for both the plumber and owner. It’s the least labor intensive solution, when installed conscientiously. It’s called an “offset closet flange”. Most time-tested designs are offered in either a 1- & or 2-inch offset model. (This allows you to install a 12-in. toilet bowl when there’s only room for a 10-in. bowl.). This means you can also shift the centerline to either length (back and forward), (and even be able to ‘swing’ the flanged fitting latterly to the best fit.). There are many manufacturers of these fittings. They have been made for many years. At PtP’s first encounter with one, they were only offered in cast iron to be joined with oakum and poured-lead. (Caulked Joint). (Photo 1) Today that poured lead method is not legal in my State, but there remain other options. I’d like to give you a glimpse into the author’s opinions.

#1: 4-in. cast iron offset flange for caulking (hot lead and oakum).

Both the “hot lead” (caulked) cast brass and cast iron offset flanges are still available. Though where they would be sanctioned is question Number One. And, is that particular talent needed to perform this hot-lead caulking process, well, presently swimming in your plumber’s pool? The author believes working this old, outdated hot-lead joinery was least labor intensive when facing a closet flange replacement, on slab.
 
If I were to be living on slab, and it involved my bathroom, and I still had the needed yarning and caulking irons, and there was enough oakum and ingot, I’d probably do that last, one, joint…that way. Done properly, this method provided optimal joint strength that the toilet bowl, on ‘finish’ installation, could be held sufficiently rigid and water tight on the finish floor by the strength of this poured lead method, alone, without the need of flange-to-floor fasteners. (That is no longer an option.)  With ‘that’ no longer being reality, and now being governed by fewer choices, I’ll think out loud about some of our options.
 
Iron Pipe
 
If you’re faced with installing an offset flange on an iron pipe (slab and ofg) then the compression no-hub flange is an option (PHOTO 2). This design of fitting can be found composed of iron or a combination of iron and brass, with stainless bolts.

#2: 4-in. compression cast iron offset flange

These cast iron and cast iron/brass compression flanges may be used with both no-hub iron pipe and with some tweaking, Schedule 40 plastic DWV pipe. The outside diameter of Schedule #40 plastic pipe is a slightly larger diameter than the no-hub iron pipe. By taking apart the flange and warming up the rubber gasket in hot water for a few minutes you can fit most of them to plastic.
 
The only situation where PtP needed to employ a no-hub compression fitting (offset flange) on #40 plastic pipe was for slab. (Before you do this I recommend you consult my book: Installing and Repairing Plumbing Fixtures.)
 
Band Seal Design
 
A big concern of the author is: how securely can the flange be attached to the pipe? The above mentioned cast iron/brass compression flange, when conscientiously installed with sufficient torque on the stainless steel draw-bolts, has the required strength to maintain a water tight seal with a wax ring on finish floor.
 
The gripping strength of a compression flange though, is not equal to the strength of a no-hub offset flange (Photo 4) secured with a BandSeal (Photo 5). However, this combination uses so much altitude that it is relegated solely to ofg construction in most cases.

#4: 4-in. No-Hub cast iron offset flange

#5: A Mission Rubber Co. BAND-SEAL Specialty Coupling used with No-Hub iron pipe and fittings. Special Note: This brand and type of coupling is offered to connect myriad pipe and fitting materials of numerous diameters.

Altitude
 
Altitude, as a concept for plumbers, was discussed also in both of my books. For those installing an offset flange, in slab, this issue of altitude (how much of it are you using up?) is more critical. Here, the farther you can offset latterly in inches, using the fitting requiring the least depth (of hole), the easier your chore will be.
 
In slab, the plumber chips away the concrete to accommodate not only the circumference (outer shape) of the fitting, but also the depth into the crete necessary to get flush with the floor. The less this height (altitude) factor is, the easier on you. Compression flanges (Photo 3) are your “shallowest” option.

#3: 4-in. cast iron compression offset flange inverted

If ‘chipping-out” ended up making a hole all the way through the slab, all around the riser (past the edge of the flange), when re-pouring the new crete, you have the opportunity to use the 3 or 4 factory screw holes in a cast iron/brass flange rim. By employing brass closet bolts, threaded tightly to the flange, flats up, bolts down (Illustration 1), with nuts and washers under, the new crete has anchor points to grip.

Illustration 1: Arrangement of brass or stainless steel closet bolts, washers and nuts fastened to rim for anchoring in concrete re-pour. ALL 6 or 4 holes in rim should host assembly.

#11: A Push-In style PVC offset flange with stainless steel adjustable rim. Note: It is imperative that all flange-to-floor screw holes be employed with stainless or brass screws of appropriate/effective length with these Push-In models. The author made note in the text that with inverted, bolted, brass closet bolts, nuts and washers he would employ this flange in a crete re-pour, although it’s designed to be anchored to wood floors.

In ofg it’s usually sawdust in the eyes but more options of flange (size/bulk) you can employ. Also, in ofg, you can achieve a better/stronger flang-to-floor installation by screwing the flange to a wood sub-floor. (Photo 4, above) is a 2-in. offset no hub flange. This is my favorite but usually not suited with the shallow dimension of slab.
 
It is attached to pipe with a no-hub style coupling, which wraps around the outside circumferences of pipe and flange discharge. When I employ a Mission Rubber brand Band-Seal Specialty Coupling (Photo 5, above) to join the no-hub flange to pipe, I’ve got the strongest connection I can make in a tight spot.
 
Plastic versus Plastic
 
Both plastics and politics begin with the letter, P. We cannot escape the fact that our choice of DWV pipe and fittings is politically driven. Two powerful lobbies. ABS versus PVC. When the plumbing you are trying to save is PVC or ABS, when installed and inspected, whatever existed most likely was the piping material choice for that bailiwick. When called to rectify the “string line mistake” yours truly has no plastic versus plastic political affiliation. If Schedule #40 PVC were sanctioned for DWV in my bailiwick, my below-slab choice (now no hub iron) would switch to that PVC. But, as that is not my present option, one of the several following choices of offset closet flange suffices  compression cast iron or iron/brass (as mentioned), solvent weld PVC, solvent weld ABS, and Push-In designs (Photo 11). Let’s take a look at our options.
 
Solved by Solvent
 
The solvent used in conjunction with the cemented PVC process, in numerous ways, is a big minus in the calculation for which plastic (ABS vs. PVC) to employ for DWV in above grade framing, if there were a choice. The vapors of the PVC primer and solvent cement are extremely potent and should not be breathed for long. (Once ruled a plumber’s biggest occupational hazard). This primer also melts many of the plastic gloves found in the construction materials dealers’ inventory. Yet, Schedule #40 PVC is so much stronger than ABS in both chemical resistance and pipe wall integrity that I think meeting responsible ventilation concerns merits its application especially for below slab piping.
 
Finding both ABS and PVC offset flanges to cement onto 4 inch diameter pipe, via hub, is rare. (Photo 6) Is one of those rare, full throat 4-inch, hub (over pipe) ABS offset flanges. 3-in. PVC and ABS versions that are called: 4 x 3 are far more common (Photos 8 & 9). What this means is that the fitting will cement to a three inch pipe, via hub (over the pipe) and glue into a 4-in. pipe bore.

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#6: A rare 4-in. hub (over pipe) 2-in. ABS solvent weld offset flange with adjustable rim.

#8: A 4 x 3 PVC offset flange with adjustable Stainless Steel rim. Note: The smooth hub of this fitting will cement into the bore of 4-in. pipe.

#9: An ABS ‘4x3’ offset flange (2-in.) with adjustable Stainless Steel rim, showing dimensions.

Without needing a tape measure, these 4 x 3 fittings usually give themselves away because they do NOT have raised letters and identification marks on the outside of the hubs, like all other standard fittings. This allows you slide this hub into a 4-in. pipe, after both have been properly treated with solvent and/or cement, and result in a good, watertight joint. Having this two pipe size option is handy but the author prefers not to reduce the inside diameter of a 4-in. pipe by using this 4 x 3 choice.
 
ABS welds (melts) the pipe and fitting together. (A skilled plumber, with considerable experience can sometimes salvage a pre-welded ABS fitting.)  PVC pipe and fittings are of much tougher material than those of ABS. But they are considerably heavier than ABS and require closer spacing of supports when hung from off the ground framing. There is a specially blended {pink or green colored) transition cement for joining PVC to ABS. This allows you to cement flange and pipe of the different materials, ABS/PVC. When used, depending on ambient temperature, long cure times (8 to 12 hrs.) can be required before a water test or use. As a homeowner, you might find a plastic offset flange that best fits your physical circumstances but is not the same as your pipe. You can fly under the radar and use the transition cement but be sure to follow the cure time requirements, to the letter.
 
Push Ins
 
The majority of these flanges are either PVC or ABS and not iron. They have an elastomeric, external bottom seal, usually one or more grooved rings. (Photo 10)  The underwritten versions of these beauties are for use with 4-in. pipe. Their only means of being secured in place requires screwing to sub or finish floor, which makes them a poor choice for slab retro fit. (However, with a large, thru-slab cavity around a riser, and with inverted closet bolts as discussed above (Illustration 1) the author would consider this flange for a slab.

#10: An ABS flange with conspicuously marked Stainless Steel adjustable rim.

But their downside in the author’s eyes is the choked-down passageway due to the space taken up in the pipe by the seal/s. I would also feel uncomfortable employing, on this flange, anything but a (great flushing action) high efficiency toilet like a Toto or like performer. In past writings the author has made known his opinion of 3-in. drain pipe. (In his mind, aside only vertical closet drops, it doesn’t exist but for shower and laundry lines, AND for this, rarest of occasions.)
 
Flanges and Screws

#7: A 3-in. hub only ABS offset flange with powder coated adjustable rim. Note: Take note of the bulge in the back-side of the fitting. This closet offset flange is sized to pass the 3-in. ball test.

Photos 7 & 9 above, depict a 3-in. (over pipe) ABS offset flange with an adjustable, steel, powder-coated rim (in this case a handsome red/orange). Because of the raised letters and I.D. on the hub of this specimen, it would not be warrantied to insert into 4-in. pipe. (Not perfectly sized like a 4 x 3). The author installed countless plastic flanges with these powder coated rims. I suspect the vast majority to still be on the job. However, since steel corrodes much faster under a toilet than iron does, I have also seen countless failed plastic, powder coated steel flanges. I suspect improper installation to be the number one cause. However, now that these plastic flanges are available with adjustable stainless steel rims (Photos 8, 9, & 10, above) I strongly recommend them over powder coated versions
 
As far as screws, you would be foolish to employ any but stainless or brass. If you have six holes or four, fill them all and never scrimp and size their length accordingly.

Play Ball!
 
Whatever material and size of your offset closet flange, it must be able to pass a 3-in. diameter rigid ball. This is a late requirement. Many which could not meet that requirement have been installed. The mere offset of the flange is already impacting the quickness (and efficiency) of the flush. Why impede it an iota further? To my knowledge there is not yet a plumber’s 3-in. test ball for offset flanges, but you should inquire from the supplier if the ones they sell, do meet this criteria. I’m sure it’s been given a definite ASTM.
 
The H Grail
 
With all the choices of flange we have there are still situations where none of them adequately covers your need. What would be the Holy Grail of offset flanges? ANSWER: a 4-in. (with bushing, fits 3-in)  telescoping/compressing, with a 360 degree swivel and fully adjustable rim, adaptable to all piping choices, with a wider than standard, non-corrodible rim with 6 to 8 countersunk screw holes. All of you mechanical engineering students…Get Busy! 
 
 
PtP