Washers on toilet flange

I have a cast iron toilet flange that does not have any screw holes for fastening to the floor. It does have some slots that are wider than a screw head, though. I was thinking about installing some screws with large washers to provide fastening to the floor (see picture). Is this a good idea or a bad idea? (I know that flange would ideally be screwed down through the tiles).

Thanks,
Tim

I see nothing wrong with you idea. You will need to drill holes through the tiles as large as the screws. Then use #12 stainless steel screws that are long enough go go clear through the flange, tile, and sub floor. I's use 4 screws. Use stainless steel washers too.

Looks like the flange could be installed two different ways. The slots being used to for the bowl bolts could have been used to secure the flange down but since it works the other way, awesome! Be sure to use stainless steel hardware.

kingsotall said:

Be sure to use stainless steel hardware.

Click to expand...

Or, Brass.

flanges

Cast iron flanges are assembled so rigidly that they do not need securing.

I was wondering about that - so only 'plastic' flanges require securing to the floor?

Tim

If it is hot poured ( oakum and lead joint) it does not need to be secured to the floor. In the Illinois code they say it only needs to be secured in these cases. Bold in the paragraph added by me.

Section 890.360 Water Closet and Pedestal Urinal

Fixture connections between drainage pipes and water closets, floor outlet service sinks and pedestal urinals, and earthenware trap standards shall be made by means of brass, copper, hard lead, plastic, or iron flanges; caulked, soldered, screwed or solvent welded to the drainage pipe. Flanges of hard lead, plastic and iron flanges for no-hub or compression joints shall be secured to the floor. The connection shall be bolted, with a gasket, washer or setting compound, between the earthenware and the flange. The floor flange shall be set on an approved firm base. The use of putty or non-drying plumber's putty manufactured specifically for plumbing installation is acceptable.