This is in continuation to post # 57002.
@Shahid.
@SI.
The 3/8 dia Iron/Steel bars (Suggested by brother SI) between the walls on both sides of the cavity will form a Thermal Bridge between the two walls & reduce the Thermal Insulation of the cavity. Further these bars will rust/corrode with the passage of time.
The best choice would be Plastic or Wooden bars of the REQUIRED STRENGTH to hold the two walls in position. Plastic Bars will be the best choice.
Regards.
How-many-bars replied on Monday, January 2, 2012 06:34 AM
And now the question rises as to how many bars should be used per square meter of the wall area? |
AG replied on Monday, January 2, 2012 07:23 AM
@How-many-bars.
A structure engineer will be the right person to advise you on this subject.
Regards. |
SI replied on Monday, January 2, 2012 02:43 PM
Dear AG
I fully agree with your recommendations to use wooden or plastic bars for better insulation. Actually I was referring to some houses still under construction in our township using steel bars at 2 ft. interval both vertically & horizontally.
Thanks for your great contribution for this website. Regards |
AG replied on Tuesday, January 3, 2012 02:42 AM
Dears the other & perhapes the most important thing is that the cavity must be sealed perfectly (100%) for ever & the air inside the cavity must not come into contact with the atmospheric air otherwise this cavity will be rather harmful than helpful. In Pakistan masons & labour (even supervisors-sometimes) do not take such important things seriously. The owner must make sure that the cavity is sealed properly. He must not accept "Oh Jee Khuch Nae Hooda".
Regards |
How-many-bars replied on Tuesday, January 3, 2012 03:49 AM
@AG
I appreciate your contribution. Thank you for your valuable advise. |
Ali Doha replied on Tuesday, January 3, 2012 11:49 AM
Practical /Professional advise:
Better option is to use wire mesh (any available Jali 2~4 mm Ø, recommended is GI mesh) at full width of wall (4.5"+2"+4.5" = 11") at interval of one Insulation sheet height (2 'approximate) . Mesh to be embedded in 1" cement sand mortar or concrete with small aggregate. Using this will all cavity will divide in small panels and get very good wall strength. Even in this if workmanship is not good/not closed /sealed any panel will not be any problem. This is my practical experience ant some project done in my supervision. Insulation 2" thick also called Thermopore or polystyrene (all are same)is very necessary when some one want to construct cavity walls for Thermal (Temperature control) and Sound proofing. Block Masonry 4.5" thick both cavity walls should not be less than CSM 1:4. One thing more necessary is fixing of Electrical Conduit pipes during construction in side cavity walls at insulation space because if after closing cavity walls fixing of conduits in 4.5" thick walls will minimize the strength of wall and also will be difficult. |
Mian Sahib replied on Tuesday, January 3, 2012 03:11 PM
Actually links can be made with 1/8 inch dia GI wires bent in butterfly shape (which is the standard recommended shape) with 8 inches total finished length & 2 to 3 inches width of wings at the ends will be good enough. Being G.I there will be little chances of rusting & corrosion. Standard spacing of these links is 36 inches horizontal and 18 inches vertical, placed zig zag. Being a practicing structural engineer, this is the specification that I have been recommending to my clients for the last 2 decades at least. |
