Concrete Column Clamps (1961) Ltd. v. Demontigny Inc. et al., [1976] 1 SCR 541

Supreme Court of Canada

Concrete Column Clamps (1961) Ltd. v. Demontigny Inc. et al., [1976] 1 S.C.R. 541

Date: 1975-01-28

Concrete Column Clamps (1961) Limited (Defendant) Appellant;

and

Adrien Demontigny Inc. (Plaintiff) Respondent;

and

Jean-Louis Caron, Claude Bourgeois and René Martineau Mis en cause.

1974: March 25; 1975: January 28.

Present: Laskin C.J. and Martland, Ritchie, Pigeon and Beetz JJ.

ON APPEAL FROM THE COURT OF QUEEN’S BENCH, APPEAL SIDE, PROVINCE OF QUEBEC

Fault—Liability of contractor—Contract at fixed price—Collapse of building under construction—Subcontract for forms and supports—Overloading—Subcontractor not responsible—Civil Code, Arts. 1684, 1688 and 1065.

Respondent was general contractor for a building under a fixed price contract and appellant was his subcontractor for the forms for the concrete slabs and their supports. Post‑stressed concrete beams were specified as supports for the three upper slabs so as to avoid any interior columns over the first slab. The reinforcing of each of these beams consisted of two steel wire cables each placed in a thin metal sleeve. These cables, when tensioned as required between anchor cones at each end, would put all the load onto the foundation walls, through the reinforced concrete structure of the peripheral walls. However, so long as the cables remained untensioned, the load was of necessity supported by the basement slab, through the forms and their supports. Nearly all the interior structure collapsed, including a good part of the basement slab, just as pouring of the roof slab was being completed and before tension had begun to be applied to the cables of beams in the other slabs. The Superior Court, upheld by the Court of Appeal, found that the collapse occurred from yielding of the form supports, and not from rupture of the basement slab, the latter being only a consequence of the former, and it ordered appellant to pay damages to respondent. Hence the appeal to this court.

Held: The appeal should be allowed.

The true cause of the collapse was the overload imposed through the fault of respondent, who did not

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tension, or cause to be tensioned, the cables of the beams in either the ground floor slab, or the first floor slab, before pouring the concrete for the roof slab, contrary to what was intended. The general conditions of the contract hold the respondent liable in the event of overloading which causes an accident. Appellant was under no obligation to furnish supports capable of withstanding this overload, of which neither it nor those who had the power to contract on its behalf were forewarned, and which it was not obliged to foresee.

Audette v. Guérard & Guérin (1912), 42 Que. S.C. 14; A. Cohen and Co. Inc. v. Industries Brandon Limitée, [1959] Que. S.C. 63; J.A.Y. Bouchard Inc. v. Gagnon, [1968] Que. Q.B. 803; Hill, Clarke-Francis Ltd. v. Northland Groceries (Quebec) Ltd., [1941] S.C.R. 437, referred to.

APPEAL from a judgment of the Court of Queen’s Bench, Appeal Side, Province of Quebec[1], affirming a judgment of the Superior Court. Appeal allowed.

D.H. Wood, for the defendant, appellant.

Roger Thibaudeau, Q.C., and M. Beaumier, for the plaintiff, respondent.

The judgment of the Court was delivered by

PIGEON J.—The appeal is against a decision of the Quebec Court of Appeal which affirmed a judgment of the Superior Court condemning appellant (Clamps) to pay respondent (Demontigny) $86,779.26 for damages resulting from the partial collapse of the structure of a building under construction. The action was also brought against the architect, Caron, and the engineers, Bourgeois and Martineau, but Demontigny did not appeal the decision affirming the dismissal of the action against them, and appellant Clamps sought no conclusions against them. They are therefore not really parties to this appeal though a notice of appeal was served on them, and they were not represented at the hearing.

The building under construction was the Trois-Rivières Normal School. The damaged portion was a wing measuring approximately 124 feet long by 61 feet wide, and 47 feet high above the foundation. The structure of this wing was of a

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very special design. It was an innovation in reinforced concrete technology. Mention was made of only one other building in Quebec in which this technique had previously been used. This innovation consisted of using, to support the ground floor, first floor and roof slabs, what were called pre-tensioned concrete beams. In actual fact, the concrete was post-tensioned, because according to the specifications, the tension was to be applied only when the concrete had attained a resistance of 4,000 lbs./sq. in., or about 18 days after the pouring.

It must be added that the balance of the structure had ordinary reinforcing placed in the forms before pouring. This is how the basement slab was built, it was a monolithic structure of ordinary reinforced concrete with integral beams supported not only on the peripheral foundation wall, but on interior columns as well. Pre-stressed concrete beams were specified as the support for the three upper slabs so as to avoid having any interior columns over the first slab. The reinforcing of each of these beams—with a span of about 60 feet—instead of being made of steel rods embedded in concrete, consisted of two steel wire cables each placed in a thin metal sleeve. At the time of pouring these untensioned cables, placed longitudinally, offered no resistance, but once tensioned as required between anchor cones placed at each end, their effect was to be to put all the load onto the foundation walls, through the reinforced concrete structure of the peripheral walls. However, so long as the cables remained untensioned, the load was of necessity supported by the basement slab, through the forms and their supports.

The accident occurred on April 21, 1961, just as pouring of the roof slab was being completed. Nearly all the interior structure collapsed, including a good part of the basement slab. Tension had not yet begun to be applied to the cables of beams in the other slabs.

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Demontigny was general contractor for the entire job. Clamps, or more precisely, another firm whose obligations it assumed, was its subcontractor for construction of the forms at a unit price. Demontigny claimed from the latter for the damage caused by the accident, alleging that it was the temporary supports or jacks holding up the forms, which gave way. The defence, while alleging that the general contractor did not apply tension to the beams in each slab before pouring the slab above, maintained that the collapse was due to rupture of the basement slab, not the yielding of the form supports. The lengthy hearing at first instance was concerned essentially with this question, of which was the first to yield, the basement slab or the form supports. Two of the expert witnesses called by Clamps were Gilles Vandry and Roger Beauchemin, engineers, who immediately after the accident, acted on a commission of inquiry established under the Public Inquiry Commission Act (R.S.Q. 1941, c. 9, now R.S.Q. 1964, c. 11). The trial judge dismissed the objection to their testimony in support of the theory that the slab had ruptured first. However, he preferred to accept the view of other experts, remarking that:

[TRANSLATION] The fact remains, however, that a member of a Commission, already aware of the facts and possibly having heard expert witnesses and given judgment, could not have the same objectivity as an ordinary expert, that is to say a specialist who approaches the problem at issue without any preconceived ideas, in order to inform the Court on a technical or scientific matter. Accordingly, the Court does not attach as much importance as it might otherwise have to the testimony of Gilles Vandry, if he had merely been an ordinary expert witness. This applies also to his fellow members of the Commission.

If the other experts, not members of the Commission, had been experts appointed by the Court, I would have no hesitation in accepting this reasoning. However, that is not the case. The other experts were engineers whose services were secured either by plaintiff Demontigny, or by other defendants having an interest opposed to that of Clamps, namely the architect and the engineers. I find it difficult to see why the opinion of experts retained

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by the parties should be considered as offering a greater assurance of objectivity than that of members of a commission, charged by governmental authorities with inquiring into a technical problem within their specialty. How can it be suggested that they did not approach the matter without preconceived ideas, when they based their testimony only on their own findings? It is alleged that in their inquiry they heard testimony which constituted hearsay; but the fact is that more than one witness heard in Court stated that his deposition at the inquiry shortly after the accident was more accurate than that given in Court nearly five years later.

However, in view of the concurrent findings of the Courts of Quebec as to the material causes of the accident, I shall refrain from making a detailed review of the evidence in order to determine whether those findings are well-founded. In spite of the doubts which I entertain as to the criterion adopted by the trial judge in weighing the opinions of the expert witnesses, and as to the logic and scientific value of the reasoning which led him to a finding contrary to the opinion of the members of the Commission, I must admit that there is abundant evidence in support of his finding of fact which was affirmed by the Court of Appeal. This finding was that the collapse occurred from yielding of the form supports, and not from rupture of the basement slab, the latter being only a consequence of the former.

This does not dispose of the appeal, as a basic question remains, which was clearly raised in the pleadings but of which almost nothing was said. This question is: Even admitting that the collapse occurred through yielding of the form supports, should responsibility for this be attributed to the subcontractor who supplied them, or to the general contractor who overloaded them by tensioning neither the ground floor slab nor the first floor slab, before pouring the concrete for the roof slab? In the engineering reports filed in the record, the principal concern was with establishing which yielded first, the form supports or the basement slab. That was the material aspect of the accident.

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However, as this is an action in damages, what has to be determined is legal liability. To do this it must first be determined what rule must be followed in the circumstances. The Civil Code contains specific provisions of great importance on the question of liability of the contractor to the owner. The two most important articles are:

Art. 1684. If the workman furnish the materials, and the work is to be perfected and delivered, as a whole, at a fixed price, the loss of the thing, in any manner whatsoever, before delivery, falls upon himself, unless the loss is caused by the fault of the owner or he is in default of receiving the thing.

Art. 1688. If a building perish in whole or in part within five years, from a defect in construction, or even from the unfavourable nature of the ground, the architect superintending the work, and the builder are jointly and severally liable for the loss.

Under the first of these provisions, Demontigny was clearly liable to the owner, namely the provincial government, for the loss. What of the liability of the subcontractor to Demontigny? Should we merely apply the ordinary contractual rule, by which damages are only due for breach of the contractual obligations (Art. 1065 C.C.)—the rule being that exceptional provisions apply only to the cases expressly mentioned. Should a distinction be made between the case of a subcontractor, who takes the place of the general contractor, and assumes his obligations, either for the entire job or an identifiable part of it, and one who only undertakes to assist in performing the work? There is not a great deal of judicial authority on this point. Besides two judgments of the Superior Court, which refused to allow the principal contractor to rely, as against the subcontractor, on the principle of art. 1688 C.C. (Audette v. Guérard & Guérin[2]; A. Cohen and Co. Inc. v. Industries Brandon Limitée[3]), there is a recent decision of the Court of Appeal (J. A, Y. Bouchard Inc. v. Gagnon)[4], in which it held that the Court should apply, in

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favour of the general contractor against his subcontractor for installation of a heating system, the principles applicable to the owner’s remedy against the principal contractor, as they were stated in the decision of this Court in Hill, Clarke-Francis Ltd. v. Northland Groceries (Quebec) Ltd.[5]. In that case Taschereau J. formulated the rule as follows (at p. 445): (as translated in [1941] 4 D.L.R. 314 at p. 321)

There is no doubt, therefore, that the owner of the building is not bound to prove fault on the part of the builder when the work was done by contract, but that the latter can free himself from responsibility by proving that the damage is due to either force majeure, an Act of God, the fault of the owner or the act of a third party.

Without deciding whether this statement must necessarily be applied in the same way between contractor and subcontractor, it may certainly be said that the latter must at least be entitled to raise those grounds of defence against the contractor. Of those grounds, the one that must be considered here is the fault of the contractor himself. It is established beyond any doubt that the act leading to the accident was the failure of the principal contractor to tension, or cause to be tensioned, the cables of the beams in either the ground floor slab, or the first floor slab, before pouring the concrete for the roof slab. The principal contractor was responsible for this omission. He had the responsibility for co-ordinating operations. It was he who decided, without consulting Clamps, to pour the concrete on all slabs before tensioning, contrary to what was originally intended: this was established beyond question.

It was also clearly established that this was the cause of the damage. No one disputed that it had the effect of putting onto the basement slab and the form supports the entire weight of the three upper slabs, and not the weight of one slab only. Gilles Demontigny, an engineer and secretary of the Demontigny company, stated:

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[TRANSLATION] …If we had worked upwards, the pretensioning on the ground floor slab could have been—the start of pre-tensioning on the ground floor slab could have been made fifteen (15) days after March 28, about fifteen (15) days after March 28; as soon as it was seen from the concrete tests that would have been made that the concrete had attained four thousand (4,000) pounds, we could have started pre‑tensioning on the slab. Before the concrete could attain the required four thousand (4,000) pounds, which the engineers required of us, at least fifteen (15) to eighteen (18) days were required. Now, fifteen (15) or eighteen (18) days after the slab was poured, pre-tensioning on a slab itself could have been started; pre-tensioning on a slab like that may take about a week, a week and a half, it may be as much as two (2) weeks, with the concrete grout that must be placed in each sleeve. Then, other slabs would have been prepared in due course. The same thing would have been done after the concrete had attained its four thousand (4,000) pounds. Now, by starting the pre-tensioning with the roof instead of with the ground floor—all the concrete would have been placed in our slabs, and would have been held up by the supports and forms of Concrete Column Clamps, and once the roof concrete had attained four thousand (4,000) pounds, about fifteen days after April 21, pre-tensioning would immediately have started, fifteen (15) days after the 21st, on the roof, and once the pre-tensioning on the roof was done, the forms going from the first floor to the roof would have been removed, and pre-tensioning would have been done on the first floor; once the pre-tensioning was complete, the forms below would have been removed, and work would have started on the next slab.

The trial judge, for his part, said:

When the accident took place pre-tensioning on the three upper slabs had not started, so that the basement slab was supporting 345 lbs./sq. ft., the base of the columns four thousand (4,000) lbs./sq. ft., and the base of the walls, one thousand (1,000) lbs./sq. ft. On these figures the experts were agreed.

Once pre-tensioning on the upper slabs was completed, the major portion of their weight would have rested on the base of the walls, while the column bases would have borne a little more than the actual weight of the basement slab.

To this it should be added that the load of 345 lbs./sq. ft. on the basement slab was nearly three times the design load of that slab, which was only 125 or 128 lbs./sq. ft.; all the expert witnesses

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agreed on that. In a report made to Demontigny by The Warnock Hersey Company Ltd., and filed as Exhibit P-28 there are, on p. 5, calculations for the basement slab:

safe superload—128 p.s.f.

It is true that in the same report the rupture load is estimated at 500 lbs./sq. ft., and it was concluded from this that the overload was not sufficient to cause the collapse. It is this latter point on which the expert testimony disagrees. However, even admitting that the safety factor of the basement slab and its supports was large enough that the overload did not cause them to rupture, does this mean that the overload was not a negligent act? Does this mean that the principal contractor, who is responsible for having imposed it, can blame the subcontractor for not having prevented the consequential damage? In my view, this is the real question in the case at bar.

On behalf of Demontigny it was argued that the subcontractor had an absolute obligation. But this is equally true of the contractor with respect to the owner, and does not prevent him from avoiding liability by showing that the damage was due to the fault of the owner. The question then is whether the failure to tension the beams of the lower slabs was a contractual or quasi‑delictual fault.

To answer this question it should be noted, first, that the “General Conditions” of the principal contract contain the following clause:

[TRANSLATION] 33. OVERLOADING

No part of the structure shall be overloaded with a weight greater than that contemplated and calculated for such structure. If the contractor applies an overload and an accident occurs, he shall be held liable. Any temporary support shall be as resistant as if it were meant to be permanent.

No load shall be placed on the fire proof floor before it is completely hardened.

Then, in clause 7 under the heading of pre-tensioned concrete, it is provided that the pre‑tensioning shall be applied about 18 days after the

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pouring. Finally, no one said that good practice did not require that the tension be applied upwards, to each of the slabs in turn, as was intended according to the testimony of the first supervisor of the work, Lucien Bélanger, who said:

[TRANSLATION] In Mr. Demontigny’s office, which was a trailer at the time, in the trailer which was being used as Mr. Demontigny’s office, mention was made in my presence only once of the fact that the pretensioning was to be applied upwards.

Then, we must consider what obligation Clamps assumed under its contract. The work for which it was responsible is described as follows:

[TRANSLATION] TO furnish labour, equipment, materials and everything required for complete construction of the forms, the whole at a unit price as follows:

To furnish, erect and dismantle all forms necessary for standard slabs between the beams, and furnish supports required in connection with laying of the concrete.

All work to be at the applicable elevation

Standard slabs at 0.25/sq. ft.

Hung slabs for boiler room at 0.30/sq. ft. of surface

Hung curved slabs for chapel at 0.75/sq. ft. of surface

Standard column at 3.50/column

Walls: to furnish, erect and dismantle all necessary forms, tie rods, and so forth, between pilasters (unit price 0.29/sq. ft. of surface)

all applicable taxes included

Did this contract place on the subcontractor an obligation to furnish sufficient supports under the ground floor slab to bear the load of not one but three slabs? To answer this question I will quote from the testimony of Gilles Demontigny, an engineer and secretary of the company:

[TRANSLATION] The fact of proceeding with the three (3) slabs without applying tension which holds up the three (3) slabs, one immediately after the other, is something that… that our forms subcontractor is not in the habit of doing. What they ordinarily do—is that there are only two (2) slabs supported simultaneously, whereas there, under the basement slab, supports, jacks, were left to hold up the basement slab. They had jacks which went from the basement to the ground floor, and they had jacks from the ground floor to the first floor,

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and from the first floor to the roof, something which experts on forms do not ordinarily do. They keep only two (2) floors on ordinary reinforced concrete, two (2) floors which still have supports.…

When the pre-tensioning is done upwards, they remove the supports immediately after the pre-tensioning is applied.

To this must be added what the engineer Maurice Décarie, then general manager of Demontigny, told the Court concerning what occurred during the reconstruction:

[TRANSLATION] The intention of the general contractor was to apply pre-tensioning downwards after the collapse, and the subcontractor Concrete Column objected to this method, and in view of the objection of the subcontractor we thought it best to proceed upwards. They objected in writing to that method. So, in view of the subcontractor’s objection, we thought it best to proceed upwards.

It was established beyond question that the decision to apply tension only after the three slabs above the basement were poured was taken without the subcontractor being consulted. No mention of it was made in the “Site meeting minutes” drafted by Demontigny, and the latter did not inform Clamps of it by letter or otherwise.

On behalf of Demontigny it was argued that, even if the subcontractor was never informed that the tensioning would be applied upwards, it could not have been unaware of this, since its foreman and workmen could see that the tensioning cables were not taut. However, these facts were not thereby brought to the attention of representatives of the subcontractor who were authorized to contract on its behalf, or who might have reasonably been assumed to be authorized to act for it. The obligation to place sufficient supports under the forms of the ground floor slab to bear the load of two other slabs over that slab is manifestly more onerous than what could have been foreseen when entering into the contract. All the evidence indicates that the number of supports necessary is calculated according to the load that each can bear, and as we have seen, supports are ordinarily provided only for two slabs at a time. Also, it could not reasonably be assumed that the foreman and workmen of the subcontractor, who had previously made forms

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for construction in ordinary reinforced concrete only, were in a position to understand and fully appreciate the consequences of a lack of tension on the cables. The following is a revealing extract from the testimony of Maurice Décarie, an engineer and then general manager for Demontigny:

[TRANSLATION] Q. NOW, Mr. Décarie, were there any outward indications making the method chosen apparent? Could someone familiar with the matter observe at some point that the pre-tensioning was being done from the top rather than from the bottom?

A. Outward indications—I do not think you could say from looking at the structure, that you could say whether the tensioning was done from the top or from the bottom.

Q. You don’t think so?

A. No.

Q. There were no outward indications that would show to someone familiar with the matter which method had been selected?

A. Well, to someone qualified, certainly there were outward indications. To a layman there would not be any. To a qualified person, the cables were visible, and at the ends of the sleeves, to a person who understands pre-tensioning methods, certainly, it was easy from looking at the structure to tell whether the pre-tensioning had been done or not.

Moreover, the fact that the tensioning had not been applied was apparent from outward indications only after the concrete of the first slab had hardened. Therefore, this fact was not known to Clamps’ employees at the critical time, that is when they were setting up the supports under the first slab, those which are said to have yielded. The argument of knowledge acquired from an obvious fact is therefore illfounded.

It should also be noted that the evidence was that it is not usual to make detailed calculations of resistance for form supports as is done for a permanent structure.

In my view, in undertaking to provide forms and supports as it did, the subcontractor Clamps assumed an obligation conditioned by the provisions of the specifications and workmanship prac-

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tice. The following provisions are found in cl. 5 of the subcontract:

[TRANSLATION] The plans and specifications forming part of the documents of the contract between the Owner and the Contractor shall be binding on the Subcontractor with respect to all matters pertaining to the work described in this subcontract and the general conditions of the contract between the Contractor and the Owner shall be binding on the Contractor and the Subcontractor in so far as they are applicable to this subcontract.…

What this means is that the principal contractor was under an obligation to the subcontractor not to put an overload beyond the design load. There would have been no overload if tension had been applied to each slab before pouring concrete for the slab above. This was demonstrated in the reconstruction, and in not insisting after a refusal, Demontigny implicitly admitted that the subcontractor was not obliged to furnish supports capable of bearing the weight of three slabs.

I do not think the slightest importance should be attached to the evidence that certain supports or jacks were defective. For that to affect the outcome of the case, it would have been necessary to show that those defects would have brought about the collapse of the structure without the overload resulting from the failure to tension cables on the lower slabs. The evidence was to the contrary: the failure only occurred as pouring the third slab was ending.

In short, in my opinion, the true cause of the collapse was the overload imposed through the fault of the principal contractor, plaintiff-appellant Demontigny, and hence it cannot recover the resulting damages, even though the form supports were what yielded first, not the basement slab. In my view the subcontractor, appellant Clamps, was under no obligation to furnish supports capable of withstanding this overload, of which it was not forewarned, and which it was not obliged to foresee.

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For these reasons I would allow the appeal, set aside the judgment of the Court of Appeal and dismiss the action with costs throughout.

Appeal allowed with costs in all Courts.

Solicitors for the defendant, appellant: Wood & Aaron, Montreal.

Solicitors for the plaintiff respondent: Girouard, Beaumier, Richard & Roberge, TroisRivières.

Solicitors for the mis en cause: Amyot, Lesage & Associates, Quebec.