Friday, December 28, 2012

Engineering Series - Twin Villa Series I and III leaking landing walls

Greetings from Australia! I hope everyone had a great Christmas holiday and/or celebration. This is a special post, written by my husband and aims to share tips on preventative maintenance of properties. Hope you'll find this useful.

Hi Residents and owners,

This is the first of a series of posts which seek to address issues / defects and preventative maintenance for properties in East Ledang.

IMPETUS: As many homeowners have been facing, defects seem to be normal walk of life in buying properties here (in our case, East Ledang).

Defects are the result of poor design, workmanship or inadequate defect repairs. In so many cases UEM maintenance team will simply 'paint over" providing only a cosmetic remedy,where the defect will only re-appear months later (subject to season) (tips for potential buyers, make sure you pay special attention to defects warranty and fix processes with UEM/your developer before you sign the purchase contract).

Equally unqualified or experienced UEM employes are ill prepared to investigate let alone resolve the root cause of the defect. Hence we decided to resolve these outstanding issues in our building ourselves but also take the opportunity to apply preventative works which reduce potential risks and significantly extend regular maintenance schedules (e.g painting)

DEFECT: Twin Villa Series I and III stair landing water moisture issue/s

Water inclusion (where it is not supposed to be) can destroy the integrity of a structure and damage finishes. We have had issues with our stair landing wall showing signs of moisture. This often results in secondary efflorescence (salting bumpy surface on the wall and possible ponding or pooling of water in the stair landing area) See figure 1

After reviewing a number of possible causes for moisture in the concrete (esp. 2 years after the build), this issue had been tracked down to incorrect installation and/or sealing of the windows by UEM in the original build. The frame seal between the aluminum window and the wall framing has not been sealed correctly and in many cases is the source of the moisture (silicone on the glass will not remedy the issue)

THE FIX Fortunately the repair is both relatively cheap and easy. A few tubes of acrylic paintable multipurpose sealer (10-15 MYR), masking tape and Sika brand acrylic waterproofing compound (looks like thick paint) will do the trick.

Masking tape is applied on the exterior aluminum window frame to protect the finish of the frame, also makes the whole repair process cleaner and easier.

After the masking tape is applied, run a bead of acrylic sealer in the joint between the frame and the concrete structure. Apply liberally as the excess will be wiped off with your finger and if need be a damp cloth. This creates a flexible seal which can manage shrinking and contraction as the building heats and cools. See figure 2

The next step prevents surrounding concrete 'leaching' moisture in behind the window. Apply by brush and roller a liberal coat of Sika Waterproofing compound around the sills and 300mm around the window, ensuring there are not holes, gaps and the compound covers the gap sealer you applied previously. This extends the waterproofing beyond the window area and in conjunction with the gap sealer ,creates a water tight seal all the way up to the window frame.

For extra peace of mind, a membrane can be used on the base sill to increase durability of the seal against movement of the building. See figure 3

After a few days of drying, a good quality exterior paint can be applied (original exterior wall colour) to finish the job.

Basic items are available from the local hardware store in Gelang Patah. Sika products can be obtained from Lin Hoo hardware in JB (Sika® RainTite®).

Best of luck! Thanks for reading.... Ian

Figure 1
Water inclusion from window sill. May not be as visible, moisture can leach without being seen.

Figure 2
Masked window frame (yellow tape) and gap sealer applied (white)

Figure 3
Waterproof compound applied (with fibre matting) on lower exterior sill

Figure 4
Waterproof cover surrounding the windows, ready for final colour coat.


  1. Hi Everyone,

    Just to share more information of aluminium window installation. Above issues or rather to say problem is mainly because of window outer frame installation before wall plastering. There are two type of outer frames in market.

    1. Single outer frame system with 25mm gap to structural opening. To be installed by temp fixing to wall and leveled before injecting concrete into frame voids for forming a line or perimeter of concrete step barrier inside frame. Then, finally wall plastering coming to meet frame edges forming a small 5mm gap for silicone sealants.

    2. Double outer frame system with only 10mm gap to structural opening. Usually to be used on precast concrete wall opening, which requiring only skim coat as wall finishes. However, a small subframe (conceal frame) to be installed first before wall skim coat by using impact anchor to wall. This small frame profiled like a step to prevent water flow in. It will receive wall skim coat before final outer frame to be installed onto it.

    I guess developer's contractor was using technique no.1 but chose to sequence site works differently. There could be wall plastering coming first, frame installation later. Then, more spraying wall coating to cover wall crack plus more silicone sealant to edges of windows (temp water proof solution as silicone will not last for long). I can say it is easily fail any SG BCA CONQUAS water test, not to mention if this building is a highrise or seaside with those wind pressure.