Design and Specification 2 Flashcards
Tameside Court: What live loads were there?
- Electric wheel chair delivery vans
- forklifts
- Vehicles
Tameside Court: Why was the gradient secondarily defective?
The drainage channels were draining though not very well and required extensive maintenance due to blockages.
Grating’s were being ripped off via shear and compression as they were undersized for the use of the surrounding occupants i.e. light industrial. As the existing gratings were for Class B.
Tameside Court: What statutory requirements did you consider?
BUILDING REGULATIONS: I considered approved document H3, Section 3.
- Gradient no less than 1:150 due to the size of the drain to comply.
- 100mm drain would have been sufficient for the area though the system I specified come 150mm minimum.
CDM DID NOT HAVE APPLTY DUE TO SINGLE CONTRACTOR JOB.
Tameside Court: What other systems did you consider?
Functional Requirements : 100mm at 1:100, Considerations:
- ACO S100 System w/ integrated falls
Heavy duty
Middle price
Integrated falls cheaper setting out, less error. The site lent itself well to this option. - ACO S100 System Standard
Heavy duty
cheapest material cost.
Did not provide integrated falls therefore longer site setting out. Had the falls been correct the site would have lent its self well to this proposal. - ACO AS1050 System standard - (Concealed system) Standard (non-integrated) falls therefore longer site setting out
More expensive
Ground may needed to be reinforced at conceal therefore SE involvement. - Concrete system - client didn’t like the look of this.
Tameside Court: Whats an F900 Load class and why did you propose this?
Refers to BS EN 124 which classifies gulley gratings and their testing loads.
F900 Used where particularly high wheel loads are imposed such as aircraft pavements.
I considered lower classes, D400 suitable for cars and lorries.
Cost between the systems was minimal.
I presented both options to the client and the client decided to opt for the full belts and braces option and over-specification to ensure the gratings were successful and that the costs were minimal.
Tameside Court: Did you consider a concrete grating system?
This was discussed during the initial consultation but the client didn’t want to use that system as they didn’t like the visual characteristics.
Kingsway House: what other systems did you consider?
UPVC system - Cheaper, not as robust as UV causes installations to become brittle and seals will weaken. Wont freeze so fit for purpose. Can be damaged by impact (lots of trees around at KH) 15 year life expectancy.
(Alumasc) Aluminium GX system = Robust, corrosion resistant, lightweight (lighter than steel), 40 year life expectancy.
Steel or copper - Considered but both too expensive.
Kingsway House: Did the works had to conform with B regs?
Yes - specifically Doc H.
Works were non-notifiable work under Schedule 4.
Kingsway House: what was on the technical data sheets?
Performance
Visual options (colour etc)
Jointing method (joggle joint selected)
BBA approved.
Discuss the requirements of Approved Document H relating to your summaries?
H3 Applied to my examples.
Rainwater gutters:
Calculated gutter size and frequency of downpipes by size of the roof surface and by multiplying the geographical areas rainfall intensity by the part of the roof, this will determine the quantity of size of the gutters and downpipes – the roof areas can be altered to use different size gutters and nr. of downpipes.
Surface water drainage:
Calculate the gradient and pipe diameter by determining the rainfall intensity of that area. Generally the more of a gradient the smaller the pipe, such as 1:10 gradient with a 75mm pipe is suitable for an intensity of 28 and the 1:80 gradient with a 150mm pipe is also suitable for an intensity of 28.
