Re: 4" or 6" concrete hollow blocks (CHB)

If we are talking of structural strength of your three storey house, for exterior, use the 6" CHB. For your perimeter fence, you can use either the 6" or the 5" CHB. And for your interior partitions, use the 5" thick CHB, that will be sturdy enough specially when plastered and perhaps will appear thicker when applied with some interior faux stone cladding, say in your living room or dining room. :agree::cool01:

Hope this helps ! 😉

Re: 4" or 6" concrete hollow blocks (CHB)

hi,

first, the disclaimer: im not a civil engr, but i have acted as an oversight to project management teams of construction projects.

this is how i understand it: it all depends on the design. if the beams and columns are designed to carry the load, then it does not matter what you use for the partitions with respect to structural integrity. so you could use 4, 5, 6 in chbs or even wood and plywood for partitions and need not worry about strength, assuming again the structural parts are designed properly. however, if the walls are designed to carry load, then use load-bearing chbs and not just the regular ones.

Re: 4" or 6" concrete hollow blocks (CHB)

With respect to fire safety, 6" CHB with empty cells has only a fire rating of
1 hour (NBC: Section 603). 4" CHB with empty cells rates even less. The
Code minimum (in an R-3 zone) is 2 hours, prescriptive of 6" CHB with grout-
filled cells and plaster. As an added note, firewalls have to extend .4 meter
or more above a roofline (some municipal Building Officials require 1.2 meters)
and there are rules about where (zonewise) you can/cannot use firewalls;
minimum setbacks from the property line; drainage for firewall runoff; etc.

As you can imagine, a groutfilled 6" CHB wall weighs a great deal, and the
structural frame has to be well-designed to support it. CHB walls themselves
require not just dispersed steel reinforcement (deformed rods inserted at
horizontal and vertical intervals), but reinforced-concrete bond beams every
10-12 courses laid (although in Filipino homes, it often takes less than 12 to
fill the height between one floor beam to another above).

This brings up an important point, that chris77 has already touched upon:
Although they do provide minor support and stiffening in real life, CHB walls
are generally disregarded as structural elements during the design process:
they are not counted on to bear loads, unlike footings, tiebeams, columns,
girders, floorbeams, roofbeams and roof-framing members.

Fire safety aside, the main drivers for CHB wall thickness are moisture, heat
and sound insulation. The first two chiefly account for the 6" thick CHB wall
recommendation (cells fully grouted) routinely made for exterior walls.

In general (not addressed to TS in particular):
Money saved in construction may be lost manifold in backjob waterproofing
and repainting, in utility bills for heat remediation (air conditioning, etc.), in
pest control, or (God forbid) reconstruction following catastrophic material
failure.

The things I'd change on your list are pure electives.
-I'd save money on the perimeter wall via 4" CHB.
-I usually design for 6" CHB upper floor exteriors, but I understand the extra
cost: 4" CHB, grout-filled, fully-plastered and waterproofed, will serve.

.

Re: 4" or 6" concrete hollow blocks (CHB)

As long as your deformaed bars, beams, colums, and concrete are properly designed in accordance to building codes and standards, you are safe.

Re: 4" or 6" concrete hollow blocks (CHB)

As long as your deformaed bars, beams, colums, and concrete are properly designed in accordance to building codes and standards, you are safe.

True. CHB has no structural bearing unless you are using jack bilt or any structural CHB(at least 700 psi).

Try 5", not as bulky as 6" but not as thin as 4".