Load bearing clay tile wall-1915 2

[WWTEng]

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?

 

[hokie66]

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.

 

[SlideRuleEra]

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

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[concretemasonry]

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.

 

[hokie66]

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.

 

[shobroco]

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.

 

[WWTEng]

Thank you all for very informative input.

Sliderule: Thanks for both the links.

 

[shobroco]

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.

 

[WWTEng]

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.

 

[BAretired]

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

BA

 

[WWTEng]

@ 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.

 

[racookpe1978]

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.

 

[BAretired]

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

 

[WWTEng]

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!

 

[BAretired]

That makes at least two of us.

BA

 

[JAE]

Three

 

[MikeE55]

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.

 

[hokie66]

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

 

[msquared48]

Thank Goodness!

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com