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Load bearing clay tile wall-1915
2

Load bearing clay tile wall-1915

Load bearing clay tile wall-1915

(OP)
Got a call from an architect earlier today about this situation with an existing clay tile wall from 1915. The contractor was removing and replacing the brick veneer because the veneer was bowing out, when they discovered that the clay tile was in really bad shape. The tile appears to be T-shaped, probably 10” deep (hard to tell). I have attached some picture to see if anyone has ever seen a tile like this.

I am trying to get a hold of some masonry restoration contractors to get some opinions, but also want to do my homework. So, in terms of fixes, short of demo and replacing what other options would we have?

RE: Load bearing clay tile wall-1915

(OP)
last pic shows the deteriorated brick ties.

RE: Load bearing clay tile wall-1915

Photo #4 is the scariest. It looks like there is hardly any wall left near the bottom. Not much of a bearing wall.

Another question is: what is the shape of the wall below grade? It may not be practical to preserve the clay tile.

One possibility is to use pneumatically placed concrete (shotcrete or gunite) to fill up all the voids in the clay tile with brick ties secured to the new concrete. Any soft clay tile would have to be removed first. There should be enough roughness in the clay tile to get a decent bond to the new concrete.

I would be sorely tempted to remove and replace the existing bearing wall. This could be done in small sections so that the entire wall does not have to come down at once.

BA

RE: Load bearing clay tile wall-1915

Are you sure this is a bearing wall? The surrounding cast-in-place concrete does not appear to be circa 1915, nor does the brick. Do a little more research on the building to verify then shore the stair area and replace the wall.

Structural clay tile was fine a hundred years ago, but we've learned a few things since then.

RE: Load bearing clay tile wall-1915

(OP)
Ron: There have been some renovations over the years but the Arch was 100% that the wall is from 1915. He will have some original drawings come Monday, so we'll see.

BTW, on the other side of the wall is a gym. So the bottom of the interior FF is probably 12' below the bottom of this wall. Without drawings its hard to tell what the below grade construction is but there is a brick layer along the entire height of the wall on the inside.

@ BARetired: grouting inside the cells would have to take place horizontally. I am not sure how easy would that be plus I am wondering if shrinkage of the grout within the cells would a problem.

RE: Load bearing clay tile wall-1915

I have to agree with both Ron and BA here.

If this is a brick building with concrete floors as I suspect, with that degree of degredation on a supposed bearing wall, I would expect to see at least two things:

1. Cracking in the top of the floor slab at the first interior support, and

2. Local diagonal cracking of the brick wall above the floor slab.

Did you not any distress like either of these things?

If you don't wee it, either it has not deteriorated far enough, which I seriously doubt, or the wall is nt a bearing wall, but an infill wall, perhaps with some intermittent black iron pipe columns intermittently cast into the wall, with a CIP concrete beam over.

Mike McCann
MMC Engineering
http://mmcengineering.tripod.com

RE: Load bearing clay tile wall-1915

That's an awfully deep steel beam to be bearing on that wall alone.

Sorry, but I still think either the steel beam is cantilevered, or there is an embedded pipe column in the wall.

Mike McCann
MMC Engineering
http://mmcengineering.tripod.com

RE: Load bearing clay tile wall-1915

I would expect Mike is correct, i.e. that there is a column under the steel beam.

BA

RE: Load bearing clay tile wall-1915

I doubt there is a column there, as the steel bearing plate is larger than you would expect for a column cap plate. They didn't even get the beam centred on the bearing plate. "They don't build them like they used to" is a good thing in this instance.

RE: Load bearing clay tile wall-1915

(OP)
Did clay tiles have standard sizes back in the day or could their have been some custom shapes too?

RE: Load bearing clay tile wall-1915

It may not be a steel column under the beam, but it could be concrete fill within hollow clay tile.

BA

RE: Load bearing clay tile wall-1915

BA - it appeared from the other photos that the clay tile was laid on its side so there were no vertical cores/cells to infill like we normally think with concrete masonry.
With that size of steel beam, I would also doubt that the clay tile could take such a load.
Clay tile like that traditionally was used as a basic infill wall material and not as a structural bearing wall unless the tile was laid upright with vertical cells and lots of vertical walls. In this case, being laid sideways, there was only the outer face shells to take any vertical load.

RE: Load bearing clay tile wall-1915

(OP)
I had a chance to look at the existing drawings and I did not see a column of any sort. There is a note for a 3/4x12x16 brg plate which seems about right and the beam is 28x105 I Beth ( probably Bethlehem steel).

RE: Load bearing clay tile wall-1915

(OP)
But I guess my first thought was on the right track, which is to remove and replace the existing clay tiles. It would be impractical to grout. they can probably do this in small sections and thats where I have my next question. What is the typical opening size that they should use to knock out the old wall and replace. Should this height be of a fixed max horz dimension full ht or should there be a limit to the vertical dim too?

RE: Load bearing clay tile wall-1915

I would look at shoring the whole thing, especially under that big beam and any other beams. Because you have a lot of window openings in the wall, it doesn't lend itself to hit and miss replacement.

RE: Load bearing clay tile wall-1915

WWTEng - Terra Cotta did come in standard sizes. Your photos look like components for "Segmental Terra Cotta Arches" that were used for a purpose which they were not intended. Their typical purpose was to fireproof the under side of concrete floors supported with steel members. I have attached the appropriate 10 pages from the 1917 Carnegie Pocket Companion that shows the various sizes of terra cotta arches and explains what they were designed to do.

BTW - The properties of the Bethlehem 28 x 105 are listed on page 44 of "AISC Iron & Steel Beams, 1873 to 1952" which you can download from this page of my website:
http://www.slideruleera.net/contributions.html

www.SlideRuleEra.net idea
www.VacuumTubeEra.net r2d2

RE: Load bearing clay tile wall-1915

Based on the photos, it appears that the terra cotta block have 2 different heights as laid and the length along the wall is shorter than most tile. Based on the condition and layout, I suspect the tile were original and later construction, as evidenced by the dimensions, condition and configuration were topped with the recent concrete.

Despite the orientation, the clay block have been used for decades for moderate loads because of the multiple cells since they were normally laid in a full mortar bed. I have seen 4 story apartment buildings built using similar units in the last 15 years. The details are not the "canned" American details/concepts, but they do work well.

I owned a architecturally significant home that was built in 1917. The structural walls were very similar 10" thick clay block with horizontal tiles. One story flat roof with interior roof drains. The foundation as the old 12x6x24 concrete block. The ceiling heights were 9'+ plus the tile continued up about 3' to support the real roof (that carried the external snow loads) and was pitched to the center to the interior drains. The interior of the exterior walls was full 2x4s with horse hair insulation and then lath and plaster with a 1/8" "china coat". The exterior was stucco. No money was spared in construction and the pristine birch Greek 10" dental trim was never stained or varnished, but was painted from day one, just as all trim was. As an example, the 8'x10' sun room had 8 casement windows with copper weatherstripped interior windows that had to be changed seasonally.

As far as the original poster's subject property, it appears the recent modifications were not well carried out (an abortion?)and the clay was used as just an existing minor support material with little regard to drainage, which caused the deterioration. In the short term, a weatherproof cementitious coating combined with correction of water control with provide years of life until the ultimate use of the aging structure can be determined.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

RE: Load bearing clay tile wall-1915

Dick, did you look at the photos, particularly the third one? That bearing wall appears to be carrying a lot of load, particularly where beams bear. I don't think a temporary solution is indicated here.

RE: Load bearing clay tile wall-1915

Shore it & replace it, but make some changes to other elements as well. The tile are worst at grade and under the steps, where they get the most moisture. Is there de-icing salt & freezing involved too? You need proper through-wall flashing below the steps and a drainage layer & dampproofing between the masonry and the paving. Get the asphalt removed back down to the original grade; the wall might be correctly built to that height. They have paved up to the first tread on the stairs to the right, so they have buried 8" of wall that was intended to be above grade.

RE: Load bearing clay tile wall-1915

(OP)
Thank you all for very informative input.

Sliderule: Thanks for both the links.

RE: Load bearing clay tile wall-1915

Here is a couple of pages from Ramsey & Sleeper Architectural Graphic Standards 6th Edition (1970) showing various tile. Your brick was not laid into the tile, just tied with metal ties. I've looked at your photos some more & I think any repair will be short-lived without properly dealing with moisture. You can't change the moisture moving through the wall (no insulation or vapour barrier) but you can prevent it getting into the wall from the steps and from the paving at grade. The ties have rusted off all over, but the tile themselves are breaking down where there is more moisture. You should also consider refastening the existing brick to the tile everywhere with retrofit ties like Helifix.

RE: Load bearing clay tile wall-1915

(OP)
shorboco, thank you.

The area has been shored and I'll let the masonry restoration guy figure out how to replace the damaged tiles. Personally I want to replace the whole wall but that may be impractical. I do want to put a steel column under the beam, the idea of two point loads coming down on this "pier" bothers me, but then again it has been around for 97 years.

RE: Load bearing clay tile wall-1915

Two point loads? I don't understand. What is the reaction of the steel beam? Where is the other point load?

BA

RE: Load bearing clay tile wall-1915

(OP)
@ BA: Right above the beam you'll see a masonry pier. There is roof girder bearing at that location, so in reality there are two point loads coming down in the vicinity of this bearing plate.

RE: Load bearing clay tile wall-1915

Can you weld a short (12 to 18" long) extension to the exposed end of the beam, using a modern equivalent to the old Beth Steel member?

Then, outside of the (almost useless wall), add a vertical column of good steel - well-anchored into a new concrete pad - to hold up the beam.

That is, you try to transfer the weight of the load + beam from the wall to the extended beam at both ends (both ends and the middle (if possible.) Yes, you'd have to jack "up" the beam 1/16 to 1/32 to actually transfer the load, but the small risk of excess cracking as the beam is lifted is balanced by the current "down" cracking settlement already has caused.

RE: Load bearing clay tile wall-1915

Is it possible that the steel beam is supported inside the wall on a separate foundation so that it cantilevers to the wall and picks up the roof load? In other words, do you have a framing plan for the floor at beam level?

It would be incredible if the clay tile wall is carrying a large load without help.

BA

RE: Load bearing clay tile wall-1915

(OP)
BA, yes I do have the farming plans and I looked at the beam from the inside of the building too. It spans from wall to wall over a gym area (supporting auditorium) aprox 54'.And exactly a story above it, is a similar long span beam supporting the roof. And again, no column on the drawings and none I could see in the field.

I don't understand how it worked for 97 years!

RE: Load bearing clay tile wall-1915

That makes at least two of us.

BA

RE: Load bearing clay tile wall-1915

Three

RE: Load bearing clay tile wall-1915

I have seen this tile used as late as 1950. It was typically load-bearing with concrete beams cast at the top of the wall. The beams would be lightly reinforced so that they could span as a lintel, but not much further. It was laid vertically where cells could be grouted and reinforced, but the installations I have seen had very little reinforcing. It is usually combined with a floor system called Toupette Tile, which is like a clay tile pan system for forming the floor. No steel or concrete columns in the buildings I have seen. The finish on an interior wall would be plaster. I never had any information on strengths for the tile, but it always looked weak to me. I have seen some similar tile in South America used recently.

RE: Load bearing clay tile wall-1915

You guys are just not old enough to understand this stuff.

RE: Load bearing clay tile wall-1915

Thank Goodness!

Mike McCann
MMC Engineering
http://mmcengineering.tripod.com

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