By John Lam Asset Enhancement • Building Technology • Uncategorized • • 0 Comments

Part 1 : Coating materials for Aluminium cladding – Non-Combustibility

From natural anodisation technique to PVF2 coating technique , the aluminium finishing coating has undergone a lot of revolutionary advancement. In recent years, there came with the discussion about “Self-cleaning” of the aluminium coating surface. This is about the coating materials which gives effect to flush its’ surface every time in raining. “Self-cleaning” is indeed a merchants’ name . The behind sciences are varying from among different manufacturer.I have conducted some comparison among some cladding’s surfaces being applied to different “treatment” allegedly claim the self-cleaning properties.  In my small research , some coatings are sheet- applied on the surface of anodised aluminium cladding. Unfortunately, my research (limited online data searching) cannot conclude sheeting-applied one was made up compilable to the Section E clause 10.1 of FS code or as per the BS476 -part 4. Well, many peers have messed up the concept of BS476 – PART 6 / PART 7 which is about spread of fire to BS476 – part 4 which is non-combustibility .

 

There are some testing to confirm “non-combustibility”. The FS code of Hong Kong does a job to cite a reference table E1 to facilitate the conversion between BS and European standard . There are many building in Hong Kong are cladded with aluminium-panel externally , but the lack of attention is paid to its “non-combustibility” requirement. Example like “self-cleaning” sheet lining or coating or spray-paint applied materials and even the fire – ratardard which are applied on external architectural features. The add-on materials on top of the aluminium are sometimes commercially attractive in term of ease of application and its price but to the sacrifice of fire safety.

Fire accident in Grefell Tower, London

Photo : Wing On building in Sheung Wan was reported to have cladded with non-combustible cladding. Source from ejinsight on the pulse ( http://www.ejinsight.com)

In my next blog , I shall explain in details the “self-cleaning” being applied in aluminium cladding.

 

By John Lam Asset Enhancement • Building Technology • • • 0 Comments

Protect your roofing membrane

When I was a boy, I saw the construction worker at roof heating up the Asphalt block with very bad odour smell. Bituminous asphalt were usually applied in liquid form in row by row with some over-lapping at even interval spacing. Although this materials are proven to be very weather resistance and durable once after curing and set, it is not encouraged to use in new works as per the General Specification (ASD) Clause 12.50. With the advancement of technology , there are now coming with various type of ready-applied roofing felt and some type are even in spraying form.

Nevertheless, the typical defects like blistering of membrane, sagging of membrane, incorrect surface water fall , poor outlet details , lack of backing rod for sealant in expansion, add-on structure impairing the roofing are still prevailing. These are attributed to the poor workmanship, lack of inspection and inadequate design details consideration. Indeed, even though the defects exists , it does not mean we have to end the life of roofing by complete re-roofing. A more sensible way is to carry regular inspection and maintenance than to leave the roof undue long time unattended.

 

By John Lam Asset Enhancement • Building Law • Building Technology • Uncategorized • • 0 Comments

Coring the rock stratum engineering our pile foundation

Site investigation is a term to cover a lot of aspect about the site. For the Engineer in construction site, it means the process to find out the soil and rock condition. From the project management perspective, we see the most essence is whether the quality control system is working well in place . This control system involves sampling , inspection, recording and counter-check. Although the PNAP has imposed a lot of restrains in the site investigation, the entire controlling mechanism still heavily rely on the professional site staff. The sample taken will be inspected the the engineer. This inspection is to be fed back to the Designer to confirm the design assumption of piling coincide well to what happens on site. This is the feedback loop essentially important in the entire QA process.

I witness the coring process and I can say the coring of soil / rock is not a pleasant job. Sometimes, the sample was damaged in the process, sometimes, the sample was dropped in pieces. Thus , a good sampling and coring process did demand patience by labour, right machine set up, on-site engineer inspection and recording.