I realized the wall specifications for my double storey landed house is a combination of RC + brickwork + precast panels. When I look at the progress pictures, it seems like most of the walls on the ground floor are precast panels. This kinda throws off my plans to extend kitchens / bedrooms.

1) How do I know if a prefab/precast concrete wall is load bearing or not?

2) How do contractors deal with hacking them and how would it differ in terms of cost when compared hacking normal brickwall?

Thanks!

This post has been edited by boyan: Dec 21 2020, 06:48 AM

my developer gives me a layout plan of my apt indicating which walls can hack

Meaning which precast concrete walls are safe to hack?

Or are those walls actually brick walls (which would be safe anyway)?

But yeah, it would be helpful to get that! I guess I'll need to inquire more.

This post has been edited by boyan: Dec 20 2020, 09:19 PM

Generally the RC wall are the ones forming the skeleton. The rest will be filled in later with bricks/AAC blocks.


Brickwalls sometimes even have airgap on the top so its not supporting anything useful.

Your developer should be able to advise which are RC and which are non RC in the layout plan.
Newer condos use RC structural wall for speed of construction.

This is important if you need to hack to add new power sockets/other pipe runs.

Old condos (low density) built like a double storey house on steroids/shoplot style usually just avoid the beams and columns only as majority brickwall.

Woops, I forgot to clarify that my house is actually a landed double storey terrace, not actually an apartment.

So am looking at scenarios where I might fully extend to the back both storeys, and even demolish some internal walls to make bigger room.

Here's a drone-flyby showing the construction progress (thanks to a fellow resident! https://www.youtube.com/watch?v=8l5lN_J5_ms&t=289s)



I don't see any walls built using bricks on the ground floor, so my worry is that both internal and external walls are using precast concrete. For some of these walls I might need to add new power points, or even demolish them outright for renovation purposes.

From the looks of it, I can't quite distinguish the RC structure - and my worry is that the whole of 1st floor will eventually be supported by both internal and external precast walls of ground floor - which would make all walls of ground floor load bearing = hence cannot be demolished like the typical brick wall (at least not that straightforward).

Just asking here if someone's gone thru the same experience (precast landed house slated for major reno), or anyone with construction experience. On the other hand I've also sent an email to the developer to inquire on walls as well.

my place all RC, even the hackable walls are RC

Wow. How was it when it comes to renovation (effort, cost, contractor willing to do the job etc) e.g

- drilling in to hang fixtures
- hacking to make way for additional power point wiring
- fully demolish a wall to make way for bigger kitchen / room

Thanks!

hacking away a wall but the wall has a door way, and two windows so its just the 2 lower half got a small piece of wall. Even that took 2-3 days to complete cause concrete very difficult to hack. yup make way for a bigger kitchen, want to join the dry and wet together as my kitchen space is super small.

got indon workers to do it. i think it cost me around 4k. need to do water proofing and retiling.

This post has been edited by idoblu: Dec 21 2020, 08:00 AM

Exactly what I wanted to do! That wall with doorway and two windows separating kitchen and yard has to go for me to join the dry and wet kitchen. Crossing fingers that kind of wall wouldn't be load-bearing, especially with it having door and windows. But 2-3 days, wow. I'd reckon it'll come off within half a day if it was just bricks.

Drilling and installing wiring should still be OK.
Just that hacking will take more effort

Indon at 4K? Wow. That's for demolishing only, or inclusive of water proofing and retiling? Wonder what's the estimated cost for just demolishing.

Lastly - curious why the need to waterproof?

share you one photo....i cant find the rest lol. price includes all labor cost and materials except new tiles

It'd be great if I can find contractor who can saw thru concrete I guess.

https://www.youtube.com/watch?t=217&v=-Fflo...eature=youtu.be

Looking at the RC they demolished - glad to see not a lot of steel rods in it, and the ones I could see are quite thin. But yeah, the concrete itself is much tougher than bricks.

Going directly to worker instead of engineer first. Waiting for house to collapse only

Did you even read the whole thing before commenting?

- drilling in to hang fixtures
Small job for couple hundred bucks will be hard to get people to do. In terms of economic sense 90% of other jobs make more money so might as well get a rotary hammer and DIY.

- hacking to make way for additional power point wiring
depending on the scope. if just hacking out one more socket 3x3 next to existing one still can DIY.
chasing if short runs under 2m can DIY with rotary hammer + chisel. then need to get cement adhesive (susu) + cement mortar to fill the chase.
if full house runs better to do it with zero furniture as all these will create a lot of dust when drilling and chiseling and some grinder edits.

- fully demolish a wall to make way for bigger kitchen / room
proper demo hammer will do it fast (Hilti and up)
china machine take a bit longer but its just a wall, not those sewage concrete box or LRT track sections so still doable, but the china machine is waste of time for deep coring usage.

This post has been edited by ceo684: Dec 22 2020, 12:12 AM

Not much of a DIY person when it comes to large projects, but yeah I guess I definitely need to upgrade my hammer drill to rotary hammer now.

For big ones, I'm gonna plan it all out during reno prior to moving in. Just a bit apprehensive in case contractors slay me with huge bill due to having to work with existing precast concrete.

https://www.12rent.my/pd-bosch-gsh-3-e-demo...hammer-650w.cfm
it should be ok but the only thing hacking off walls need time to do, so if you want to save on their removal labour you can try your hand at smashing the walls because it just need someone to operate (with proper PPE - face shield and mask of course)

Uh... I need perhaps an architect or a structural engineer to help me...

I'm looking at the floor plan and also the progress photo for my house type, and I'm wondering really if I can extend to the back both stories by tearing down the back walls.

From the progress photo you can see that the walls are prefabricated concrete panels.

So my question is - would there still be the normal skeletal beams + columns for this kind of house that's going to carry the weight?

Or the prefab walls themselves are load bearing - meaning I can't tear them down?

can you indicate which part of wall that you want to hack?

I would like to tear down the walls in red, and build the new blue walls.

Changing structure required professional input, you need to hire civil eng/consultant with PE and able to calculate and sign in order to proceed with your request unless anyone in Lowyat able to guaranty your structure stability once you modify it. They will consider all the cantilevers of the support, where is the piling and pile caps where is safe are how thick is the beam, concrete grade, soil settlement for that extension. (soil test to check soil quality only developers know normally they won't share to outsiders) RC wall is more expansive to cast compared to a brick wall, there are there for a reason you can compromise the safety factor by asking your own contractor to hack them.

Remember you and your family or someone's family is staying inside your building and you are responsible for their safety.

Anyway at this stage, you can ask the subcon of the developer if they can help you pile some point at the extension area by paying them some side earn then after they handover the developer you filly take over then you can expose the piles and make new pile caps then connect to existing beam to ensure the beam will settle with the whole building and will prevent crack.

This post has been edited by ianlti: Jun 30 2021, 12:17 PM

Thanks! Definitely will go thru proper flow (architect + council etc etc) but just want to know early on based on other people's experience with houses built with similar approach - is such renovation possible?

As long as you got the money and the developer allows without void your warranty then is fine and no complaint by your neighbor.

strata title is not possible.

I'm more curious about the structural integrity part first. In normal houses (RC beams and columns with brick walls) - ideally those walls marked red can be torn down without any issue.

I have no idea when it comes to houses built using prefab concrete panels.

If it cannot be done without seriously affecting the structural integrity - requiring me to effectively build new beams + columns to support existing floor as I tear down the walls (basically more complications than normal), then I might not go for it and just set aside the money for something else.

There are videos in the net showing how prefab are constructed. View those videos and you will know whether your plan is workable.

Looking at your plan, I dont think is possible.

From the plan n construction technique it may not be possible to delete the rc wall as it appear to be structural wall ie load bearing for the slab itself. And due to RC it doesnt stick like glue, if want to modify need to add supporting wall on the below ie new walls and u need to pour new slab for the whole back room again because concrete doesnt stick to old one.

Not all precast building is built the same way using standard components and assembly.

Unless original structural plan or as built plan is available to outsiders, only the consultants involved in the design and construction of the original building can advise if and where you can hack without adding beam.

Anybody else will take that safe approach to replace the hacked walls in red, with beam. One can't really tell from looking at limited photos and S&P plan.

Thanks everyone!

Yeah I'm thinking there will definitely be complications. I guess I'll have to wait for the handover and consult the developer.

That being said - care to share existing projects of landed houses built from prefab concrete?

Maybe I can explore around and see to what extent those owners have managed to renovate their houses (although yes, it's not guaranteed to be applicable in my case).

If not mistaken, check on houses in Serenia City.

Checked. Seems like the latest one - Ariya, which is still under construction - will have some RC walls. The older ones don't seem to indicate RC walls on their brochures though.

Looking for existing, completed landed housing project examples (non-strata, of course).

Come to think of it, prefab concrete / RC walls would be awesome for strata housing in that case, since you're not supposed to extend anything. Hahaha.

Is good to see how the construction b4 completion and after to have some knowledge. But do it after fmco.

Those houses next to the elite highway would have completed. Those have rc wall but not sure what phase.

Ah scouring around I found this.

https://www.iproperty.com.my/guides/what-is...you-buy-it-faq/

Gonna look up LBS Alam Perdana

Hahaha it is a strata-titled development (not meant for extensive reno). Went on Google Maps and the only extensions I see are simply single storey extension with roof awnings to the back (definitely no two storey extension, no extended floor slab on upper floor). Pfft.

This post has been edited by boyan: Jun 30 2021, 07:30 PM

Approach your developer and enquire if your intended renovation can be done or if can give you plan indicating which areas can hack. They should check with their specialists then revert back to you. As purchaser you have the right to know. Better than asking and checking elsewhere, which ultimately is best guess only. You are the first hand buyer, and have this privilege, unlike sub sales case.

Also, their sales office may have videos on how the precast construction is carried out. Many big developers had setup their own IBS plants in the race to stay ahead of others so they should have something to show.

You should also consider DLP can be void if any hacking is done.

All good points!

Thanks! I'm slowly (but reluctantly) accepting the fact that I might not be able to demolish any of the walls (urghhhhhhhh!). I guess it's a good reminder to anyone to carefully check the walls specification especially if one has lofty ideas of renovating further.

As your walls are ALL RC, to drill wall plug holes, recommended to use a rotary hammer as impact drills meant for brickwalls will suffer like a kancil pulling a container (TEU)

So apparently some of the prefab walls can be taken down based on the developer's renovation guidance - but the walls should be cut instead of hacked.

Has anybody engaged a contractor with experience cutting non-load bearing RC walls / prefab walls?

write in to your developer,request for a set of structure and mne drawing inform them you wish to begin renovations,and usually their civil engineering engineer would have informed the developer which walls are hackable

Cutting and hacking non load bearing walls are fine,the issues are the wire and pipe run,get your contractor to scotch tape the wires and pipes running between the walls as location mark for future reference

Ideally get an digital ifc file for future references and changes and easy to store

Yup developer has provided some rough drawings, but nothing as detailed as IFC. Trying to get that from them (along with the wiring and piping info).

Anyhow found a few wall cutting services - exploring that now.