Horizontal Drain

In order to further stabilise the slopes, other than typical berm drains, horizontal drains are installed at the slopes. The purpose is to discharge out ground water if any thus ensuring the stability of the slopes.

At this project, it is decided that the upper and lower sides of the slopes to be installed horizontal drains. As per construction drawing, the horizontal drains are installed at 12m depth and 6m interval. The holes of 100mm diameter are done by using rotary drilling with air compressed method. Then the 80mm diameter of PVC pipes wrapped with geotextile are slotted into the holes.

PVC pipes wrapped with geotextile



setting up of drilling machine


operator ready to use controller to operate the drilling machine


ready to drill. seen here is the driller bit with standard extension rod of 1.5m length.


drilling process to make a 100mm diameter hole


upon completion of the hole, then the PVC pipes wrapped with geotextile slotted into the hole


final push and adjustment of the pvc pipes into the hole

Cement Rendering At Floor

This is typical practice of making cement render. In this case is cement render at balcony.

First step, ensure right slight fall towards edge of balcony. This is important so that there is no water ponding at the balcony particularly during rain.

Second step, ensure drop (between residential floor and corridor floor) is constructed as per architect drawing. For this project, the specified drop is 100mm.


spot pegging marking drop 100mm between residential unit floor and corridor floor

Then the next work is doing spot peggings of mortar. The level of finished residential floor is used as reference level for drop. So these peggings will be used to make sure finished levels of cement render correct.


mortar spot peggings are prepared to provide correct levels during cement rendering


After that on the surface of the newly laid cement render with mixture of cement, sand & water, cement powders are placed on the surface before smoothen by trowelling. This is final surface of the cement render at the corridor.


cement rendering process with material made of mixture of cement, sand and water. cement water is poured first prior to placing mortar.


cement powders placed on freshly laid mortar and then smoothen by trowelling


finished corridor floor of cement render

Installation of High Tension cable

Currently the installation work of high tension (HT) cables is on going. After careful site inspection identifying existing utilities, the suitable route of HT cables has been identified.These HT cables with supply electrical power from nearby sub station to the new sub station for this new residential complex.

The HT cables will be buried under ground with specified minimum depth as per drawing detail provided by M&E consultant. However at certain areas where there are existing utilities underneath, the depth of HT cables have to be adjusted to site condition. It is quite shallow about 2 feet and thus corrugated pipes are provided to protect the cable. The same also is applied when the HT cable crossing road.


A drum of HT cables


Corrugated pipes are used to protect HT cables


warning covers will be placed right on top of HT cables before backfill for safety

Inspecting Hill Slopes

Currently it is rainy season here which is normal every year end. However for those involve in construction line especially those working at hillside areas, they can’t sleep easy. This is because in this time landslide always happens.

Recently, there were two big disasters on landslide happened in Malaysia. One was in Ulu Yam killing 2 siblings and another one just recently happened last week at Bukit Antarabangsa in Selangor. This time 4 were killed and one is still missing.

My current project is not exceptional also, there is a big hill cut here. Previously this area was a toe of hill, but later it was cut to allow for the construction of a 6 storey block which is still under construction. The slopes is almost complete except lower part which is yet to cut. Technically we apply slope cutting 1:1.5 gradient to these slopes, provide proper drainage, plant turf on the slopes and soon will install horizontal drains.

Hill cut at my project

However for further precaution, a few days ago together with contractor we did joint inspection at this cut hill to make sure there is no clogging at drainage system as well as checking if there are signs of movements and etc. Any wild plants covering and disturbing the function of hill drains have been removed. We pray that this big cut safe and brings no harm to those reside nearby.

Earthworks, slope erosion and mud flood

Recently, I was not happy with the contractor. I had numerously highlighted to the project manager long-long time ago from the beginning of earthworks to monitor the slopes and take appropriate rectification actions if the slopes found to be not in order.

While doing regular inspection at site, I found one slope was in bad condition. The slope erodes and brings mud flood to nearby operating facilities. You can see in the photo below.

This should not happen if the contractor provides temporary drainage at the top and bottom of the slopes plus with temporary slope protection such as planting close turf on the slopes. If not repaired, this will destabilize the slope structure and will affect road works nearby. The drawings and specifications have details on these but it seems the contractor fails to follow.