The most widely-used standards for specifying concrete masonry units in the United States are published by ASTM. International. These ASTM standards. (ASTM C 1, 1, Concrete brick. (ASTM C 55). 2, 2, * Requirements may be reduced to psi average and psi for individual units. Find the most up-to-date version of ASTM C at Engineering
|Published (Last):||13 January 2013|
|PDF File Size:||10.22 Mb|
|ePub File Size:||13.11 Mb|
|Price:||Free* [*Free Regsitration Required]|
Fully mortared piers should not require cap blocks. ALL piers are installed at a right angle to the carriage beams and marriage wall and need to be centered under the carriage beams or marriage wall. Piers aatm the ends of each carriage beam need to be within 24 inches of the end of the beams. Rechecking the level of the home and tightness of the piers after shimming all piers the first time is highly recommended.
Leveling the home in one area may throw off the level aetm another. The level of newly ast, homes and tightness of its piers should also be checked after about six months and a year because the slab or footings could have settled.
A recheck should also be done if the home develops cracks in the drywall, doors or windows that do not open or close as before, or gaps in places where they were not present before.
I do not support use of them without proper soil testing or strict installation according to the. This is my document; so xstm follows my rules. Other manufacturers have slight variations. Most lateral brace manufacturers require tie down straps at the corners of single-wide homes.
C14500 Tellurium Copper Alloy | C145 Tellurium Copper Rod and Bar
At least two braces are required for each home—located near opposite corners of the home and installed in opposing directions. The exact wording is as follows:. The use of ABS pads must be used in conjunction with aztm perimeter skirting in accordance with paragraphs D 1 to D 4 and E 1 to E 6 of rule We attended this hearing specifically to voice concerns about this revision to the previous rules that did not asmt these pads.
Our assessment of the attitude of the OMHC during the hearing was that it favored the rule change.
The Load Carrying Capacity of Hollow Sandcrete Blocks | romeo klens blay –
Therefore, we wrote the letter attached to this blog post and submitted satm to the OMHC within the comment period less than 24 hours.
That letter is included here:. As the letter states, we are concerned that ABS pads will be used in conditions where they are not intended. Essentially, our concern is that ABS pads require that soil be used as a replacement for concrete footings or slab. That is to say, the soil has the same bearing capacity as concrete. However, unlike concrete, which has a bearing capacity that changes little over a wide range of conditions, the bearing capacity of soil can change dramatically.
Therefore, if soil is going to be used to astmm concrete, the soil conditions must be controlled. In the one decently documented case where ABS pads were successfully used, soil moisture and frost heave were well-controlled. The insulated skirting, moves the frost line to grade.
The required soil bearing capacity is in part essentially a requirement for proper drainage because the soil bearing capacity can drop significantly as the soil moisture increases. Thus, soil moisture needs to be controlled through proper drainage. But, can installers be trusted to measure soil bearing capacity accurately or to accurately calculate whether an ABS pad be able to take the weight put on it?
Can most inspectors be trusted to check the right parameters and review the required information. The OMHC has left those questions wide open. Currently, installers and inspectors are not required to have special training. Therefore, no two installers will be doing the same installation or checking the same parameters.
That is why we wrote the letter to the OMHC. If ABS pads are going to be used, they need to be used properly and uniformly. They cannot simply be used in place of concrete footings because soil is not exactly the same as concrete and the weight being put on the soil will usually be more for ABS pads than for concrete footings.
We are going to continue pursuing the issues of proper training for ABS pad use. We are also aiming for the requirement that a licensed engineer approve the use of ABS pads to assure that homeowners get the home that they believe they are buying.
In a future blog, we plan on commenting research sponsored by the Ohio Manufactured Home Association which has been used to back the approval of the pads. So, your brand new home was built with a crawlspace that has the vents installed according to code requirements.
Further, the crawlspace has a proper vapor barrier covering the floor. You should have absolutely NO d145 about moisture in the crawlspace, right? Here is one case where I found out in a rather uncomfortable way that a crawlspace built with proper ventilation and a moisture barrier of sorts can indeed get lots of moisture. One spring day last year, I left a meeting in Columbus astmm noon and headed toward Wilmington to do an FHA inspection on a asrm manufactured home installation.
This home was built on a crawlspace with a poured concrete slab floor. Wilmington had received light rain the morning 1c45 the inspection. The home reportedly has had drainage problems at one end; but the crawlspace was dry. By the time I got to the home, we were experiencing our usual axtm weather our springs and summers bring. This photo shows a front view of the home on the day of the inspection.
Note the right crawlspace perimeter wall. This photo shows a closer view of the right perimeter wall area, which was still having some drainage problems on the day of the inspection. When I went to enter the crawlspace, this view greeted me. Note the water droplets hanging on pretty much every surface in the crawlspace; but the slab is totally dry. And since I have a lot of pictures, here is yet another view adtm the water droplets on surfaces.
The lateral brace in the photo is the second of the pair of braces used in the anchoring system. Note all of the droplets on the bottom board the membrane along the bottom of the home. This photo shows a closer view of water droplets on bottom board—and by this time on my camera lens. Yep, a lot of water was present. And every time I raked c15 of these surfaces, I got a shower of cold water—not a pleasant experience.
Aatm photos shows that the crawlspace vents were wide-open. Interestingly, no surfaces near the vent has water on them. Where am I going with this story? All of the water droplets seen in these photos are due to condensation. The prior night, the area where the home was installed had colder temperatures and, since the home was not heated, the crawlspace temperatures were also on the chilly side. The next day, as is common in our area, outdoor temperatures climbed rapidly, as did the humidity levels, fueled in part by recent rain.
The crawlspace surface temperatures remained below the condensation point of the air, causing water droplets to form on pretty much every surfaces inside the crawlspace, except those near the vents where the surfaces apparently warmed more rapidly. I believe that this case is proof that even properly ventilated and moisture protected crawlspaces can get water in sstm.
The condensed water may have come from water vapor coming up through the slab. However, the open vents provide a more open path to water vapor in the outside air. Even if water vapor had come up through the slab, this case shows that the water vapor can be converted back into water droplets that can be absorbed by the crawlspace materials exposed to the water. Thankfully, the intact bottom board of this manufactured home prevented moisture from reaching the insulation above the bottom board.
Otherwise, the insulation could sop up the water like a sponge and hold it long enough to possibly cause more serious issues. However, this case shows that water can get inside a crawlspace without liquid water entering the crawlspace. If surfaces inside the crawlspace are below the dewpoint of air entering the crawlspace, condensation will occur.
Having vents in the crawlspace open it up to outside air which can supply the moist air. Open vents can also allow heat in the crawlspace to escape, allowing surfaces in the crawlspace to cool to below the dewpoint temperature of air that may enter the crawlspace later.
Now, if the crawlspace does not have a vapor barrier, moisture issues could be much worse. I am looking forward to the time when I enter a awtm that actually has fog—and I have been in some that were close. Oh, one other lesson I learned is that if you are going to enter a crawlspace with condensation on the surfaces, you will get wet.
Masonry Archives – Patio Drummond
In this case, I was soaked to my underwear by the time I left the crawlspace. Asfm recently had a structural inspection that showed once again how much damage a gang of termites can do to a home.
This damage was located in the rim joists and sole plates of a home with brick veneer. However, these termites had incentive to invade the wood due to the rim joists and sole plates being apparently exposed to excess water coming from behind the brick veneer. Some background is needed before getting into the termite business.
The sole plates are the boards that sit atop the foundation, upon which the first floor joists rest. Rim joists, also known as band joists, are the boards that box in the floor joists. The ends of all floor joists resting on the sole plate but up against rim joists. Rim joists asstm help stabilize the joists and help keep them from angling or twisting.
In a properly designed brick veneer wall, a gap is supposed to be installed between the brick veneer and the exterior wall sheathing. The exterior sheathing is the material that covers the outside face of the wall framing. Sheathing can be boards in older constructionor plywood or oriented strand board OSB panels, although in some construction Styrofoam panels may be installed between the plywood or OSB panels.
The gap between the exterior sheathing and brick veneer is supposed to serve as a drainage plain to provide water that gets past the brick veneer a drainage path to the base of the wall. And, believe me; water can get past the brick veneer, particularly if the brick is especially porous.
Drainage holes in combination with flashing in the brick veneer just above the foundation in the brick veneer are supposed to provide a path for water to flow out of the drainage plain. Brick veneer installed on concrete block construction, more commonly used for commercial construction, is also supposed to have a drainage plain with weep holes. Full brick exterior walls, such as those on many old buildings in Cincinnati, do not need weep holes because the water supposedly travels fully through the brick into the interior wall surface or back out to the exterior surface.
Another brick construction that was usually not built with drainage holes was concrete block on a concrete foundation with brick veneer installed in front of the block.
The brick veneer in this construction extended from the concrete foundation and up the satm wall. This last construction, as used for a crawlspace construction, is the subject of this blog post. This photo shows the concrete foundation with the concrete block above it.