Non-Load Bearing Block Partition Construction

[waters]

Hi All,

We're renovating a condo, and have a local contractor doing the work for us (so not exactly DIY).

We have two non-load bearing internal partitions that are currently steel frame and gypsum/drywall board.

We're moving both partitions, and thought that since we're at it - we might switch from steel frame and drywall, to non-load bearing block wall (we're going to hang an air conditioner on one, and maybe a TV on the other).

I was wondering if anyone here has any experience with block wall partitions, in particular if you run conduit through the wall for electrical outlets etc.

What type of block are there? Hollow? Solid? Masonry? Clay? How should the wall be capped off? And should there be a base laid on the floor fist?

Any thoughts or suggestions greatly appreciated.

[waters]

Found an excellent description of building block partition walls here...

http://www.diy-extra.co.uk/building-block-partitions.html

Still wondering about utility conduits / electrical etc... and how these are laid into the wall.

[yankee99]

they chisel a channel and lay the conduit then plaster the hole

[yankee99]

they chisel a channel and lay the conduit then plaster the hole

[JDGRUEN]

For what you describe blocks made from AAC Autoclaved Aerated Concrete would work for you. A couple of brands are made in Thailand - at least. One is Superblock ... it is light weight yet very strong -- it has a zillion very small bubbles creating air spaces in it in the concrete mass... You can do research and read about the actual manufacturing process.

But suffice it to say it is used in construction all over Thailand for infill - non load bearing walls. A thousand times better than those little bricks. You can easily hang an air con unit on it. Also - believe it or not -- the blocks can be sawed, drilled, routed, and tracks cut on the top edge for running electrical - just cut a big V notch in each block then lay them ... If there are windows - lintels should be used. Not big ugly concrete frames that one sees... AAC has a very good insulation R Value. Local building supply houses have it -- including all the big name House / Home places.

AAC is supposed to be glued together with Thin Set floor tile cement with a thin layer - but Thais have not a clue and use regular cement mortar in thick layers... The blocks have a nice smooth texture and look great. However, normally they are covered with a plaster on the interior and a stucco on the outside... And that does not mean cement mortar as is done here.. There are formulas for plaster and stucco - some involve gypsum and are used around the world. You can cover any outside stucco with water resistant paint.

I have a ton of information of this including links to the manufacturers. AAC is one of the most used forms of concrete around the world ...

[waters]

Thanks for the replies yankee99 and JDGRUEN.

JDGRUEN - this is exactly what I was looking for! Thanks a bunch, and sure - if you have some links to manufacturers that would be great too.

Actually, one of the contractors that gave us an early quote mentioned Superblock as well, so this all makes sense.

Also thanks for the tip on cutting channels 'before' the block is laid.

I'm assuming that lintels should be used above doors as well?

Thanks again

[waters]

@JDGRUEN - does the fact that Thais use regular cement mortar in thick layers have a negative impact on the wall? I wonder what my chances of success are if I were to introduce him to thin set floor tile cement.

[waters]

Some good instructions here on the Superblock Thailand site.

http://www.superblockthailand.com/service_product_menu6.html

Although they recommend 'chasing' the wall for electrical conduit after leaving the wall to 'bond' for 2 days.

"2.8 In the case where embedding the sanitary and electrical pipes will be done after the laying process, chasing tool will be used to groove Superblock by which the wall should be left for 2 days for proper bonding. Then concrete mixture can be used to fill the gap between the walls after the pipes have been embedded to the walls"

[Crossy]

Before you go building anything, has anyone considered the strength of your floor?

A block wall, even an AEC block wall, is significantly heavier than a stud and board wall, you don't want your nice new wall ending up in the unit below. Not very likely I know, but you really don't want to potentially compromise the structure of the building, do you? You really should have an engineer's report, the building management (if they're half competent) should insist on one for any renovations.

By the way, it's perfectly possible to hang an A/C indoor unit or a TV on a stud wall using the correct fixings (you need the correct fixings for AEC too).

[waters]

Hi Crossy - thanks for the reply. The block partition walls will be laid onto a concrete floor, and building management are regularly inspecting the contractors work (especially electrical). We're in a 'well-built' 2001 condo, although I will double check that we're okay to lay an AAC wall.

Have also just read that Superblock, as well as other AAC mfgs/dealers in Thailand, have technical staff that will visit sites, and advise local contractors.

[manarak]

Before you go building anything, has anyone considered the strength of your floor?

A block wall, even an AEC block wall, is significantly heavier than a stud and board wall, you don't want your nice new wall ending up in the unit below. Not very likely I know, but you really don't want to potentially compromise the structure of the building, do you? You really should have an engineer's report, the building management (if they're half competent) should insist on one for any renovations.

By the way, it's perfectly possible to hang an A/C indoor unit or a TV on a stud wall using the correct fixings (you need the correct fixings for AEC too).

yes - check strength of the floor then build a Qcon block wall - who wants stud board walls? seriously?

[waters]

Smartblock also seem to be a relatively newer competitor to Superblock and Qcon

http://www.smartblock.in.th/view_product.php?product=A001&mcat=&cat_id=137〈=en&page=1

[eyecatcher]

Lintels!!

Thats a new concept here isnt it. I have not seen Catnic or Birtley make a breakthrough here let alone your standard cheap pre stressed "P" concrete.

In your situation in a non loadbearing wall there will not be much load over a single door head so you could simply use a steel flat the same width as the wall, just give it a 100/150mm bearing at each side. no need to fanny about with shuttering and concrete thats ridiculous.

[JDGRUEN]

Lintels!!

Thats a new concept here isnt it. I have not seen Catnic or Birtley make a breakthrough here let alone your standard cheap pre stressed "P" concrete.

In your situation in a non loadbearing wall there will not be much load over a single door head so you could simply use a steel flat the same width as the wall, just give it a 100/150mm bearing at each side. no need to fanny about with shuttering and concrete thats ridiculous.

Yes - exactly...

[sirineou]

As Crossy already mentioned, drywall and stud walls are relatively lightweight and can be placed anywhere, but block walls weight a lot more and must be considered in the engineering of the structure. In two floor homes, beams are places under where block walls will be.

In apartment buildings there might not be beams, but thicker slabs maybe 8 to 10 inch thick with adequately engineered rebar.

If I was considering replacing and moving a stud and frame wall with a block wall, unless an engineer determined that the floor could support the block wall, I would at the very least use AAC because it is the lightest of all blocks, I am told that AAC block will float in water.

[eyecatcher]

, I would at the very least use AAC because it is the lightest of all blocks, I am told that AAC block will float in water.

The OP couldnt be happier now we have now also solved any potential flooding problem.

[waters]

Lol - thanks again sirineou and eyecatcher! On the 22nd floor, I'm hoping that we won't have to test the floating theory. :-)

[JDGRUEN]

In the USA the manufacturers of AAC (goes by many generic names around the world) make many different kinds of blocks. This includes a block with a deep V channel cut/formed in one of the narrow sides -- the top one or bottom as one may see it. And the gluing with Thin set is done after the conduit, cable or plumbing is installed. I have no idea why anyone would do it differently. However if one is fearful of creating a joint / seam that is not strong -- just use some vertical / horizontal pieces of rod -- even very narrow pipe, steel rebar or even plastic rebar to connect blocks. Just drill holes. I have seen plastic coated steel rods used as rebar.

Also take note with one of the vibrating cutters or old fashion keyhole saw, jigsaw and/or numerous other tools... The rectangular hole for a wall receptacle can be cut - connecting to any V channels or other types of channels cut into the block.

And in this regard the use of steel rebar for vertical or even horizontal reinforcement can be done, even between just two blocks. This kind of spreading the area to insure holding of the weight of a Air Con unit could easily be devised.

Also American makers of AAC make some with steel reinforcement already in it. Plus some blocks have big holes in them for vertical reinforcement with steel and then filled with regular concrete to produce a 3 inch or more vertical steel reinforced column in the ascending block wall.

BUT -- they do not have that here as far as I know. But there is nothing preventing one from inventing their own use of cutting holes and channels. Just keep in mind how much your are cutting away.

Finishing - as I said before - normally it is using REAL stucco and plaster. But - if the blocks were laid with Thin Set and done as Western Craftsmen can do -- that is straight. narrow, level bonding seams - then painting with an good water repellent elastomeric paint without stucco could be done... tinted to any color. The same for the interior. Of course this means the seams would show - but that would not be unusual in many circumstances.

Once in a home refurb, for a temporary time, I used exterior rain resistant elastomeric stucco paint on a shower wall clad with the cementitious tile board. It worked great - shed water like a duck.

With a little googling -- image googling one can see the great potential in an AAC wall - finishing, reinforcing, and numerous other aspects.

Although my ideas take more time in laying the block, with only a couple of walls in this job - I can't see how it would not be worth it. Thais can be trained how to use the Thin Set - just buy a big plastic tub of it and demonstrate -- make a relatively thin layer and start laying a course of blocks. Study videos on how it is done in Western Countries.

[Crossy]

Hi Crossy - thanks for the reply. The block partition walls will be laid onto a concrete floor, and building management are regularly inspecting the contractors work (especially electrical). We're in a 'well-built' 2001 condo, although I will double check that we're okay to lay an AAC wall.

Have also just read that Superblock, as well as other AAC mfgs/dealers in Thailand, have technical staff that will visit sites, and advise local contractors.

Make sure you get all permissions in writing from the condo management company.

There is at least one story on ThaiVisa where the poster got verbal permission, completed the work and then ran into serious issues with the management (to the point were some renovations had to be reversed).

[waters]

Thanks Crossy - will do. We have drawings we're going to submit to the juristic person office. Fingers crossed ;-)

[MoD1977]

Hi JDGRUEN,

it looks like you are an expert with this AAC Blocks.

I have a question:

How can i improve the sound insulation when i plan a House with these blocks?

At the moment the plans are to make the outside Walls from the House with doubble Walls (7,5cm thick blocks with 5 cm hollow space between).

I think it will be enough for the normal noise of the surrounding from the house.

The tricky part is that this house will have a build in homecinema and in there sometimes it will be a high soudlevel.

This will be the only room in the House that will have also the inside Walls build as doubble Walls same as the outside Walls for soundproofing.

The goal is to keep the rest of the house quiet when someone look at a movie inside.

My idea is that we can fill the hollow space with rockwool but i'm not sure if it helps or its a wasting of money.

What do you think?

Regards

MoD

[IMHO]

As per Crossy's advice, you'd better make sure that an engineer will approve it. Most concrete floors are only designed to support 200KG/sqm, in which case block partition walls must have a supporting beam below. The highest weight loading spec I've seen in residential was 500KG/sqm though, which would be able to do it without a beam under.

[IMHO]

Hi JDGRUEN,

it looks like you are an expert with this AAC Blocks.

I have a question:

How can i improve the sound insulation when i plan a House with these blocks?

At the moment the plans are to make the outside Walls from the House with doubble Walls (7,5cm thick blocks with 5 cm hollow space between).

I think it will be enough for the normal noise of the surrounding from the house.

The tricky part is that this house will have a build in homecinema and in there sometimes it will be a high soudlevel.

This will be the only room in the House that will have also the inside Walls build as doubble Walls same as the outside Walls for soundproofing.

The goal is to keep the rest of the house quiet when someone look at a movie inside.

My idea is that we can fill the hollow space with rockwool but i'm not sure if it helps or its a wasting of money.

What do you think?

Regards

MoD

I can maybe help on this one...

Rockwool will really only help attenuate high frequencies, which if using block construction don't really penetrate anyway (they get reflected). Bass is the real problem to contain in HT environments, and an air gap will work just as good as any filler you could put in there at bass frequencies. The most effective way to attentuate bass is to reduce/minimize mechanical coupling between your wall layers.

[JDGRUEN]

Hi JDGRUEN,

it looks like you are an expert with this AAC Blocks.

I have a question:

How can i improve the sound insulation when i plan a House with these blocks?

At the moment the plans are to make the outside Walls from the House with doubble Walls (7,5cm thick blocks with 5 cm hollow space between).

I think it will be enough for the normal noise of the surrounding from the house.

The tricky part is that this house will have a build in homecinema and in there sometimes it will be a high soudlevel.

This will be the only room in the House that will have also the inside Walls build as doubble Walls same as the outside Walls for soundproofing.

The goal is to keep the rest of the house quiet when someone look at a movie inside.

My idea is that we can fill the hollow space with rockwool but i'm not sure if it helps or its a wasting of money.

What do you think?

Regards

MoD

I can maybe help on this one...

Rockwool will really only help attenuate high frequencies, which if using block construction don't really penetrate anyway (they get reflected). Bass is the real problem to contain in HT environments, and an air gap will work just as good as any filler you could put in there at bass frequencies. The most effective way to attentuate bass is to reduce/minimize mechanical coupling between your wall layers.

Not an expert -- just knowledgeable. I would suggest reading about AAC and sound / noise reduction. There are several articles on it. AAC blocks are good at absorbing sound - but not my area of expertise - I do not know the stats on it. Suffice it to say they are nowhere near the same in reflecting sound as standard block - just the opposite. AAC blocks are filled with - not sure of the number - but seeming millions of tiny sphereoid cavities created by the hydrogen gas process that is generated in production. A google on this will tell the tale -- Sound absorbency and Autoclaved Aerated Concrete blocks...

If building a new house... the answer for your question would be to make all walls of a room with AAC, And if that is not enough add other kinds of sound proofing as has been recommended. AAC blocks are not hollow - they are solid. I am not aware of any of them that are build like the well know Haydite semi-hollow Concrete Block. There are slim versions of AAC blocks that one cold use to create a void between two layers of AAC and fill that void with other soundproofing material. It would probably also be the most well cold/heat insulated room in the house. Be careful and not make it too air tight.

[IMHO]

Hi JDGRUEN,

it looks like you are an expert with this AAC Blocks.

I have a question:

How can i improve the sound insulation when i plan a House with these blocks?

At the moment the plans are to make the outside Walls from the House with doubble Walls (7,5cm thick blocks with 5 cm hollow space between).

I think it will be enough for the normal noise of the surrounding from the house.

The tricky part is that this house will have a build in homecinema and in there sometimes it will be a high soudlevel.

This will be the only room in the House that will have also the inside Walls build as doubble Walls same as the outside Walls for soundproofing.

The goal is to keep the rest of the house quiet when someone look at a movie inside.

My idea is that we can fill the hollow space with rockwool but i'm not sure if it helps or its a wasting of money.

What do you think?

Regards

MoD

I can maybe help on this one...

Rockwool will really only help attenuate high frequencies, which if using block construction don't really penetrate anyway (they get reflected). Bass is the real problem to contain in HT environments, and an air gap will work just as good as any filler you could put in there at bass frequencies. The most effective way to attentuate bass is to reduce/minimize mechanical coupling between your wall layers.

Not an expert -- just knowledgeable. I would suggest reading about AAC and sound / noise reduction. There are several articles on it. AAC blocks are good at absorbing sound - but not my area of expertise - I do not know the stats on it. Suffice it to say they are nowhere near the same in reflecting sound as standard block - just the opposite. AAC blocks are filled with - not sure of the number - but seeming millions of tiny sphereoid cavities created by the hydrogen gas process that is generated in production. A google on this will tell the tale -- Sound absorbency and Autoclaved Aerated Concrete blocks...

If building a new house... the answer for your question would be to make all walls of a room with AAC, And if that is not enough add other kinds of sound proofing as has been recommended. AAC blocks are not hollow - they are solid. I am not aware of any of them that are build like the well know Haydite semi-hollow Concrete Block. There are slim versions of AAC blocks that one cold use to create a void between two layers of AAC and fill that void with other soundproofing material. It would probably also be the most well cold/heat insulated room in the house. Be careful and not make it too air tight.

They reflect high frequency just the same as any other block once they have been rendered.

[sirineou]

Lol - thanks again sirineou and eyecatcher! On the 22nd floor, I'm hoping that we won't have to test the floating theory. :-)

with global warming and rising sea levels one never knows

though the comment regarding the floating ability of AAC can also indicate that they are lightweight

[waters]

Okay - here we go.

Was talking to the contractor today about his plan for the new partitions and I asked him if he'd be using any 'wall profies' - to attached each end of the AAC block wall to the existing end walls.

"Wall Profiles. These metal strips are fixed to the walls at either end of the new

partition and give you something to attach the new wall onto. Remove the skirting boards along each

wall. Cut the metal connector to the correct length and fix it to the wall at the required position using

60mm screws. Use a plumb line to make sure that the metal connector is perfectly vertical. This will be

your guide to help keep your new wall vertical, so taking a bit of extra time now will save time later."

And he looked at me blankly :-)

They seem to make sense to me. Should I pick some up and 'donate' them to his efforts?

[JDGRUEN]

I found these statements at AAC product websites in just 5 minutes of searching ... and also take notice of the link below in blue...

AAC Sound absorbency and sound reduction:

Sound absorbency of air borne sound for 3" & 4" walls is 38 to 40 db. Hence, it is ideal for auditoriums and theaters and for cutting off workshop sounds from offices.

Sound Absorbent: Walls constructed with eight-inch thick AAC building blocks have a Sound Transmission Class of 45 when tested in accordance with ASTM 1190-90. This acoustic barrier, combined with the product's light weight and fire resistance characteristics make it an ideal building material for party walls and partitions separating multi-tenant dwellings. Benefit: AAC is a natural material for use as a dividing wall between movie theaters, town homes, and multi-residential apartment and condominium complexes. The inherent sound transfer benefit results in a superior finished product that is completed without otherwise necessary soundproofing products.

AAC buildings are quiet due to the mass and cellular structure of AAC walls and floors. This gives it STC ratings of 44 to 50 depending on finishing materials. Furthermore, AAC is so good at blocking noise it is used for sound barrier walls along highways.

And here is an extensive one with a web link that provides in depth information about AAC and noise reduction / absorption ... My take after reading all this information is that the issue of high frequency noise reflection is a issue looking for a problem...

http://www.mhe-international.com/aac_autoclaved_aerated_concrete_material_advantages_sound_insulation.php

[waters]

Also wondering what thickness of block we should use. Q-CON blocks come in standard sizes of 20x60cm at 7.5 10 and 12.5cm thickness. I believe the builder is going to plaster them, about 1cm each side and he's recommended the 7.5cm thick blocks. Thoughts?

[eyecatcher]

Okay - here we go.

Was talking to the contractor today about his plan for the new partitions and I asked him if he'd be using any 'wall profies' - to attached each end of the AAC block wall to the existing end walls.

"Wall Profiles. These metal strips are fixed to the walls at either end of the new

partition and give you something to attach the new wall onto. Remove the skirting boards along each

wall. Cut the metal connector to the correct length and fix it to the wall at the required position using

60mm screws. Use a plumb line to make sure that the metal connector is perfectly vertical. This will be

your guide to help keep your new wall vertical, so taking a bit of extra time now will save time later."

And he looked at me blankly :-)

They seem to make sense to me. Should I pick some up and 'donate' them to his efforts?

With all due respect "waters" I would just like to suggest you keep your new found knowledge under your hat for the time being.

Wall connectors/wall starters/profiles are generally a western product designed for tying in a new extension onto an existing building. Mostly used externally and the idea is firstly they can withstand lateral movements of around 3 tonnes but also allow the extension to move up or down approx 10mm when you get settlement of the new extension or; going the other way; ground heave.

Block and brick toothing is a common practice also (in the west) but some areas are prone to ground movement and the bricks would simply shear; as such wall connectors are mandatory in these areas.

You have a simple internal wall already sitting on a concrete floor (22 stories up!) There will be no movement in the wall other than on a drunken night where you manage to miss the doorway.

On the basis that your existing walls are already internally rendered then block bonding/toothing in the new blocks is not even a starter (no pun intended this time).

The solution is simple; you need to find a hardware shop and just use some 3 or 4" metal angle brackets; about 10-20bt each. On the first row of block, drill plug and screw thew the bracket to the wall. Then repeat the process every 3 course up to the top. Job done; and no big drama. I think your builder would do something akin to this if not exactly the same.

I have never seen wall starters here but as they are stainless steel and imported they would be very expensive.