MASONRY WEIGHT AWARENESS CHART INSTRUCTIONS

1^st Column: Width of opening in mm.

2^nd: Width of opening in brick lengths.

3^rd: Number of bricks in a full triangle of masonry above an opening of 102mm brickwork Stretcher bond when a load-point is intact.

4^th: Total weight in Kg of brickwork above an opening in a full triangle of masonry within 102mm brickwork Stretcher bond.

5^th: Number of bricks in a full triangle of masonry above an opening of 215mm Flemish bond when a load-point is intact.

6^th: Total weight of a full triangle of masonry above an opening within 215mm Flemish bond.

7^th: Total weight of a full triangle above an opening within a cavity wall, Brickwork and lightweight block work.

8^th: Total weight of 215mm brickwork above an opening in a typical 2.4m Storey height in any brickwork bond, half the weight for 102mm brickwork; add 50% for 13” brickwork.

The Brick Brace weight chart is designed for weight awareness to show the difference of the weight of masonry without a load-point and when a load point is intact.

No roof loads are included and a factor of safety of 215mm is included for the different possible positions of a new opening within an existing brickwork bond.  5Kg per brick (F.O.S 1.8) has also been added to allow for the different variety of bricks and the variations of mortar and moisture content.

All lengths over 3,150mm are for propping and bracing. When a load point does not exist every task is different and should be calculated on its own merit. If the size and weight of windows are known the weight of the windows can be added and the volume of brickwork that the windows take up can be removed from the calculation.

Load-Point

A 35 degree angle in a stretcher bond and a 25 degree angle in a Flemish bond from both ends of the opening, carrying up to the central perpendicular joint where both angles meet is the load-point.

All tasks of supporting masonry are different and must be calculated and planned carefully upon their own merit and carried out when using a variety of temporary support equipment most suitable.

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When an opening is made within an existing wall and a load point is intact the triangle of brickwork above the opening is the only masonry that could collapse and therefore the only masonry that requires temporary support.

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Upon larger openings where any of the 3 points of the triangle do not remain, this law changes and the weight of the whole storey height sits back over the length of the opening due to the masonry above not having the correct arching effect, this can weigh up to 10 times more than the smaller triangle of masonry.

Re-instate A load point

Fit the Brick Brace Safety tool through the broken triangle and it becomes complete, reducing the load to a minimum and safely reducing the number of props required, cost effective without compromising safety.

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An overloaded prop attachment relies solely on the lateral strength of the masonry of which is always different especially within lime mortars and is why the Brick Brace should be used when possible.

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The Brick Brace Safety tool increases the variable safe working loads of all the existing propping methods and addresses all the main causes of minor and major collapse during masonry alterations.

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We are available through e-mail to answer any question regarding temporary masonry support!

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Propping & needling

Research upon the paper Temporary works toolkit part 10

Carried out by Anthony Lundie

Sent to the author Ray K Filip, The H.S.E’s temporary support team & Veralum

tse@istructe.org

The calculation of temporary support during alterations is only an assumption of a permanent lintel supports calculation, which is incorrect. It doesn’t take into account that every task of masonry alterations is different and that all tasks should be planned carefully upon their own merit. Also the lateral strength of masonry is unpredictable & varies upon every task of which depends upon the length of the new opening required within existing masonry, the mortar mix, the age and quality of the masonry being altered. Within temporary works the masonry has not just been laid and can even be built within a lime mortar mix which has very little (if any) lateral strength upon wider openings.

The 45% angle of the load triangle and the 60% angle of the interactive zone are also different within temporary support works during masonry alterations and vary upon the material used and the bond of the brickwork.

45% Load triangle where a load-point is intact

440mm x 215mm block work is a 45% angle

A 215mm long x 65mm high brick in a Stretcher bond is a 35% angle and 25% angle in an English or Flemish bond.

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The 60% angle of the interactive zone should not come into play during masonry alterations when all three of the corners of the load triangle are in place as the only masonry that could collapse is this smaller triangle of masonry, therefore this is the only masonry that requires temporary support.

When any of the three corners of the load triangle (25% to 45% depending on the material and bond of the brickwork) are not in place due to no or only one reveal of masonry remaining or a load-point being lost due to impeding windows upon the floor height above, then the calculation would include all of the masonry above the opening, including roof loads & live & static loads where they apply.

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All existing propping methods rely upon the unpredictable lateral strength of the masonry to work safely which is why a task must be planned carefully upon its own merit and carried out safely by using a variety of temporary masonry support equipment most suitable and not by using the assumed calculation of a permanent lintel BS 5977.

CHECK LIST

1. What is the nature of the task, is it remedial works or fitting a permanent support? Is it forming a new opening or increasing the size of an existing opening? Is the opening in a 4″single skin of masonry, two skins or even more? Is the opening in the outer or the inner leaf of a cavity wall or in both?

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2. What is the age and condition of the masonry and what is the masonry material? What design (cavity or solid)? What is the size of the cavity? What thickness is the wall? Which bond is the masonry and which mortar mix, cement or lime?

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3. What are the existing ceiling heights? What are the size and direction of floor/joists, are they load bearing onto the wall or are they non load bearing? Does the existing floor impede the internal fitting access? What is the condition of the internal wall? Is the internal wall plastered or dry-lined or bare masonry as in the case of the majority of total refurbishments? Are there any signs of movement, e.g. cracking?

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4. What height is the opening, ground floor, first floor or higher? Is a permanent support fitted underneath joists? Are the existing joists fitted within the web of the permanent support or is the permanent support fitted at the same height or below non load bearing joists?

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5. What opening size (including bearings) is required? Is a load-point intact? What is the total weight of the load that requires support? Which variety of lintel/s steel/s are specified or most suitable? What are the length, depth, width, thickness and weight of the permanent support/s? Is the permanent support/s deeper than existing floor joist depth?

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6. How will the new permanent support be fed into position and how will any old lintels be removed? Which equipment or variety of temporary support equipment is designed to support the masonry correctly and also provides sufficient fitting work access without dangerously over extending and overloading itself?

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The more temporary masonry support methods known, the safer and easier the many different specialist tasks of supporting masonry become.

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Temporary support equipment options in alphabetical order; Acrow props, Brick Brace, Needles, Prop-Wise and tongued prop attachments.

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Using the Brick Brace in-conjunction with the traditional propping methods reduces labour & repair time without cutting corners or compromising safety, supports the masonry in between props, stabilises the masonry and also improves the unknown variable safe working load of all the existing propping methods;

 Brick Brace with Acrow props, Brick Brace with Needles, Brick Brace with Prop-Wise or Brick Brace with Strongboy’s and depends on the task at hand of which variety is most suitable. 

The Brick Brace counter acts all of the hidden problems of only propping masonry.

Forming Openings in Load Bearing Brickwork

Propriety products

No More Props;

Is a steel frame that is cut into 50% of the bed mortar joint above a proposed opening and is suggested in part 10 that it is suitable for creating openings up to 2.5m wide within existing brickwork, when the maximum opening size is only 2.3metres leaving a maximum finished opening for a door/window of only 2 metres when 150mm bearings are required.

Recommendation

This should be rectified with immediate effect.

Strongboy’s

The tool kit part 10 suggests that the maximum opening size for the use of Strongboy’s is around 3 metres and for use in less than heights of 3 metres. The Strongboy instructions have falsely eased a specialist task for 25 years and have suppressed the true level of knowledge that is required to tackle the many different tasks of masonry alterations safely, if they should not be used upon openings over 3 metres, then the Strongboy instructions of use should be changed and include the maximum opening size as does the Brick Brace safety system.

Recommendation

You must inform the H.S.E in writing to ensure the issues are addressed as the H.S.E rely solely on structural engineer organisations due to their own lack of knowledge within this field. I have also attached my professional research of the Strongboy with this research for you to read.

Due to the Strongboy tongue being approximately 155mm wide it doesn’t support all of the masonry safely when fitted at intervals of more than 300mm apart which is why the Brick Brace safety tool/system should also be used when fitted further apart as seen within the illustration below.

Props & Needles

1. It is suggested that needles should not be placed any further than 1 metre apart, is this the author’s personal opinion? As I always assumed that needles were to be placed between 900mm -1200 apart of which depends upon the task, the load and the quality of the masonry? Please clarify.

 2. Once again it is suggested that the permanent lintel design to BS 5977 is the calculation used for temporary needles upon large openings. How this is possible when it is only an assumption as the lateral strength of the masonry is unknown and varies upon every task. What is the assumed sum or calculation when either or no reveals does not exist as in the case of many new home extensions due to goal post steel design and what is the correct procedure/sequence when fitting goal posts and box steel designs as this requires further clarification. As a suggestion, the structural engineer that designs boxed steels for the rear of an existing property should provide a correct sequence of works that suit site conditions and should not be left to the unaware contractor as currently done so.

3. Figure 6 (below) is misleading and requires further information as the drawing should have a correct procedure and sequence of works connected to it. Surely the internal end of the lower needle requires packing to floor for support with the lower joists supported down to ground level using the appropriate concentrically loaded equipment. Please clarify, as this error shows how easy masonry support can be misinterpreted due to different parties (author & illustrator) working upon the same subject.

Conclusion

The assumed calculation of a permanent lintel design BS 5977 should not be used by structural engineers for eccentric propping methods with Acrow props during masonry alterations unless the Brick Brace Safety tool/system is also used of which provides further stability to the unpredictable & unknown lateral strength of the masonry.

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British legislation:

2015 C.D.M, reg19 of which includes all professions within the construction industry, even structural engineer’s, temporary works co-ordinator’s and the H.S.E.

(Temporary Works in Brief)

The builder (contractor) must ensure they have the necessary skills and knowledge and capable of avoiding risks and able to combat risks at source.

 Adapt to individual requirements, especially regarding the design of the workplace, the choice of work equipment and the choice of working and production methods with a view in particular to reduce the effect of risk on health and on safety. Adapt to technical progress, replace the dangerous by the non-dangerous or the less dangerous.

 Regulation 19

(Stability of structures)

 All practicable steps must be taken to prevent danger and ensure that any new or existing structure does not collapse or become unstable due to the carrying out of construction work.

 Temporary support must be designed, installed and maintained to withstand foreseeable loads and only used for the purposes for which it was designed for. A structure must not be loaded as to render it unsafe to any person.

Work within health and safety guidelines; respect your legal responsibilities and the welfare of others around you.

The values of The Institution Of Structural Engineers

Professional standards

We endeavour to ensure that our members are highly skilled and work to the highest level by maintaining a commitment to professional standards within structural engineering.

We strive for continued technical excellence; advancing safety and innovation across the built environment.

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A qualified structural engineer didn’t attend university to design inferior temporary support works so why have IstructE, I.C.E and the H.S.E made it strangely acceptable to prop the rear of a property on a number of over loaded mild steel bendable tongues that sit eccentrically upon a misused Acrow prop and when the obvious accident’s continue to reoccur it’s only the unaware builder that’s at fault and possibly imprisoned where accidents cause injury or fatality?

 Where my research & professional opinion is not taken seriously, I believe any future accidents are the fault of Istructe, I.C.E and the H.S.E. due to the inability to adapt to technical progress and using the wrong assumed calculations that do not cover all temporary masonry support tasks due to every task being totally different.

 “The world is a dangerous place to live; not because
of the people who are evil, but because of the
people who don’t do anything about it”.
ALBERT EINSTEIN
1879-1955

KEEP IT SAFE, BRICK BRACE.

The Brick Brace is designed as a practicable step to prevent danger, to reduce risk from a task and ensures that any existing structure does not collapse or become unstable due to the carrying out of construction work.

TWENTY ONE QUESTIONS THE H.S.E, ISTRUCTE, THE TWF & THE H.A.E REFUSE TO ANSWER!

1:

Can you confirm that a Strongboy and all similar designed products have been fully tested upon a size 1 Acrow prop, a size 2 Acrow prop and a size 3 Acrow prop? And as a Strongboy is designed for use with an Acrow prop can you confirm Acrow prop guidance is not required within the instructions of using a Strongboy especially when Strongboy’s are mostly sold with size one Acrow props through mail order due to the lower weight?

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2: Can you confirm that the drawing below is the correct way to support a cavity wall using a Strongboy?

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3: Can you confirm it is acceptable to support 9” brickwork or block work on the 215mm tongue of a Strongboy at a minimum 300mm eccentricity from the centre of the wall to the centre of the Acrow prop and when the safe working load is reduced to an unknown quantity?

4: Can you confirm that the H.S.E have not endorsed the Strongboy by allowing misleading and insufficient guidance for over twenty five years.

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5: Can you confirm it is acceptable to support one side of a cavity wall on the bendable part of the tongue when the internal skin of block work impedes correct use, reducing the safe working load to an unknown level and when safer options are available?

6: Can you confirm that you know the many tasks of supporting masonry are totally different and that the majority of tasks require far more fitting work space than the low safe working load Strongboy can safely offer when maintaining the maximum 340kg safe working load and when not dangerously removing the opening down to the full finished level without the permanent support being fitted as it increases the risk of accidental removal of loaded Acrow props during the demolition of the masonry?

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7: Can you confirm that misusing an Acrow prop by eccentrically propping a masonry wall from only one side at a minimum of 200mm from the centre of the wall to the middle of an Acrow prop is safe when the maximum permitted eccentricity of an Acrow prop is only 25mm?

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8: Can you confirm the new instructions of a Strongboy are acceptable and do not require any revision? And can you confirm the market monopoly of the Strongboy and the misleading instructions have not fixed the typical builders and retailer’s mind-set and stopped essential temporary masonry support equipment join the market place?

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9: Can you confirm that the same number of accidents and near misses would occur if a written warning was in place at the point of sale, such as; “fitting a Strongboy misuses an Acrow prop and the safe working load is reduced by at least 90%” ? And can you explain why accidents during masonry alterations are classed as falls from height & not accidents from masonry collapse? Is it to cover up and to hide the true scale of the number of accidents caused by Strongboy misuse during masonry alterations?

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10: Can you confirm that the Strongboy is safe to use when sold without written guidance especially when the internet is still full of the old out of date instructions from the unaware retailers that do not know the instructions were changed in November 2015?

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11: I have yet to see a Strongboy being used correctly on site, can you confirm a Strongboy is not designed to be misused and that no further research upon the Strongboy’s design is required and please confirm the self certification tests of the Strongboy and of the similar designed products comply with the provision and use of work equipment regulations?

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12: Can you confirm a Strongboy is designed to reduce masonry damage without being overloaded and is simple and easy to use without compromising the user’s safety? And for a level of true guidance (to raise safety awareness due to it occurring on a daily basis), what would be the reduced accepted working load in 10mm increments when exceeding the maximum 215mm eccentricity and when the safe working load of a plumb Acrow prop is reduced by 1,700kg when loaded 25mm from the centre axis? And due to dangerous misuse and risk of curving the inner tube, what is the safe working load of the Acrow prop when used for its next concentrically loaded task? Could it be dangerously reduced to an unknown level?

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13: Can you confirm that structural engineers do not specify or recommend the use of Strongboy’s when they do not provide the correct fitting work space and when the safe working load varies to an unknown level of which depends on the size of the Acrow prop used, the working height of the Acrow prop, how plumb, how tightly fitted and how far the Acrow prop is fitted from the centre of the wall? And who police the structural engineers that have endorsed the Strongboy for over 25 years, is it the H.S.E that take unsound advice from IstructE and the Twf?

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14: Can you confirm it is acceptable to change the instructions of a temporary support product and not tell anyone of the changes including the retailer’s, builder’s organisations such as F.M.B and the hire associations?

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15: A Strongboy is designed to reduce masonry damage and to reduce the number of Acrow props from the work area even though it reduces the safe working load of an Acrow prop by at least 90%, can you confirm that using a Strongboy is suitable and safe to reduce internal 1^st floor wall damage when creating an opening?

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16: Can you confirm that the misleading marketing of a product and a brand name that implies strength but physically reduces the safe working load of an Acrow prop by 90% (with no warning) and is sold without guidance and overloaded with the same amount of ease as the manufacturer says it is to use, has not contributed to the number of accidents and near misses.

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17: Can you confirm that when an Acrow prop is fitted with a Strongboy and is either overloaded, over tightened or removed away from the wall to gain further fitting work access, the task becomes dangerous as the safe working load is reduced to an unknown quantity?

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18: Can you confirm that using a mixed variety of temporary support equipment most suitable for a task is far safer than only using Strongboy’s for every task.

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19: Can you confirm that it is in a builder’s best interest for a so called competent retailer to supply Strongboy’s with no written guidance when a variety of temporary support equipment should be used and when the H.S.E are “trying” to change the mind-set of the typical builder.

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20: Can you confirm that if  Strongboy’s do not require a maximum opening size or a correct procedure then no other temporary support equipment requires it either or should all temporary masonry support equipment have instructions of correct use and correct procedures of the tasks the manufacturers claim they do?

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21, Can you confirm that the structural engineers that specify Strongboy’s even when they are not the most suitable temporary masonry support equipment for a task, has not caused the mind-set of the typical smaller builder and retailer? And can you also confirm that structural engineers and the H.S.E have not helped dangerously ease a difficult task by allowing insufficient guidance and misleading instructions of the Strongboy? And who police the H.S.E when they are wrong and at fault? Or are the H.S.E never at fault?

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We recently asked the institute of structural engineers:

“How is it possible for a structural engineer to design a task safely with Strongboy’s when the safe working load varies from 340kg down to 0kg and depends on the size of the Acrow prop used,which pin-hole height is used, how tight the Acrow prop is fitted, how plumb and how far the Acrow prop is fitted away from the centre of the wall”?

THEIR RESPONSE

“The Health and Safety Panel has discussed in great detail, and over
many e-mails, the comments that you have raised.  The Panel has taken
the time to discuss the situation and the position of the Institution.
With that the Panel thanks you for your query.

As a learned society the Institution exists to promote the art and science of structural engineering and does not comment on the efficacy of proprietary products”

Our response to the above reply!

To whom it concerns, When a builder knows eccentrically propping over 215mm from the centre of the propped wall to the central axis of an Acrow prop is extremely dangerous they will use with the correct caution and the further equipment required.

Any fool can design a work area and use prop attachments without
knowing the weight of the load and unknowingly overload by over
extending from the wall to gain further access, but to tackle a task
safely requires further preparation.

Take responsibility

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Not commenting on the efficacy of a Strongboy is why collapse is such
a reoccurring theme on site. Endorsing and Promoting by designing
temporary works with the Strongboy without correct guidance is far
from an art form, only dangerous and so nineteen eighties.

A qualified structural engineer didn’t attend university to design
inferior temporary support works so why have you made it acceptable to prop the rear of a property on a number of 5mm mild steel bendable
tongues that sit eccentrically upon a misused Acrow prop and when the
obvious accident occurs it’s only the builder that’s at fault?

The whole idea of a Strongboy was to reduce the number of Acrow props from the work area on smaller openings when suitable, and in itself, is where all the problems of overloading begin.

Every task of masonry alterations is totally different and further
fitting space is so often required than what Strongboys can safely
offer which I believe is the legal duty of the paid structural
engineer to ensure if he recommends their use for a particular task.
If more Acrow props are required than 900mm centre’s it should make the Strongboy obsolete as too many are required to handle safely and the correct method of props and needles should be used no matter what the cost as safety is so often compromised to save time and costs on too
many occasions.

We live in a society of health & safety and warnings on products which
require them, I now know (as I come across this on a daily basis) when
temporary support equipment is sold without any guidance the user
assumes guidance isn’t required.

How will builders or first time users be aware that the guidance of a
qualified structural engineer is recommended if no warning of this is
in place? It’s in the interest of every member of the institute of
structural engineers that warnings and correct guidance for all
temporary support equipment is in place when sold or hired for an
extra increase in their workload.

A prop attachment can be dangerously overloaded with the same amount of ease as their manufacturer’s say it is to use especially when sold or hired without any warnings or guidance, we created the Brick Brace safety tool to increase safety awareness and to reduce the risk of
overloading and we provide instructions of correct use and guidance
with every purchase.

The fully tested Brick Brace safety tool reduces loads by re-instating
a load-point when lost due to windows above and supports masonry
in-between props when props and attachments are suitable or when using the correct method of props and needles.

The Brick Brace safety system also supports all 91 bricks within the triangle of brickwork within a stretcher bond above a 3150mm opening (approx 14 brick lengths), at any height with no dangerously overloaded props and attachments required and because we provide full instructions of correct use only competent builders that can read and follow instructions use our system. Please read our E-Bay feedback for proof our system is making a difference to the builders that are capable of adapting and completing a task safely.

Due to a severe lack of assistance and wording from the H.S.E it has
become widely acceptable to prop dangerously and with further
assistance from structural engineers as they do not supply adequate written guidance when designing the work place.

It is in the more than capable hands of both parties to take full responsibility and to address these issues.
I am not the enemy! I am someone that looks at a problem from a
different angle, you need my knowledge and different view for progress
and I offer my assistance for free to give an unbiased opinion.

Where you do not take me up on my offer or do not reply and keep me
informed of any progress, my options become limited and I believe I
have a case and if forced I will seek compensation for the loss of
earnings due to the negligence of the H.S.E and the inability of the
learned  ISTRUCT to adapt to progress through a court of law as  the
H.S.E and yourselves have falsely eased a dangerous task by not
enforcing or providing correct guidance and obviously refuse to admit
any fault.

For the next generation of builder to be taught safely and correctly it is the duty of every structural engineer and tradesman to ensure the temporary support equipment they specify or use provides sufficient fitting work space without overstretching and dangerously overloading itself.

We do not endorse the misuse of any temporary support equipment but anyone that continues to overload Strongboy’s through over extending from the wall to gain further fitting space, we highly recommend bracing the masonry with the Brick Brace beforehand to hold all of the masonry in between props and to reduce the risk of minor and major collapse.

KEEP IT SAFE

BRICK BRACE