Why Bathroom Toilet Partition Wall Brackets Come Loose April 23 2014
After many years of noticing bathroom partition brackets pulling out of the walls, I decided to sit down and understand exactly what was happening. Luckily, my profession is to perform aerospace structural analysis so I was equipped to apply engineering principles this problem. My findings are shown below, using words to describe loads rather than numbers for simplicity.
Figure 1: Original Partition Wall Bracket with Single Row of Fasteners.
The image shown in Figure 1, above, is of a toilet partition bracket coming loose from the wall. This can be seen in commercial restrooms all over the United States. Actually, my survey showed 25% of partitions mounted to wall with this style bracket are coming loose. It is no surprise that the current trend of partition installations has gone toward full-length extrusions along the wall. That is fine for new installations, but what do we do with the older ones using brackets like the one show in the figure? One solution is to replace these with two-fastener-row brackets. The Fix-a-Stall Bracket Kit upgrades any partition wall mount. Its modular design picks up the original fastener hole locations for a professional repair. All the holes diameters’ are enlarged one size from the original installation to ensure a snug fit. Then, a second fastener is added common-to the partition for a trouble-free attachment.
Figure 2: Fix-a-Stall Bracket over a Standard (single-fastener-row) Wall Bracket.
To understand why the partition brackets pull fasteners from the wall, it is necessary to mentally stand back and look at the whole installation. Essentially, the partition was meant to lean against the wall and the wall brackets were meant to just support compression loads. The vertical load from the partition’s weight was to be supported by the pilaster, in theory. Refer to Figure 3. Red arrows represent loads needed to hold the assembly in place.
Figure 3: Theoretical Partition Support Loads.
The wall brackets could act as compression links with no loads going into the fasteners common-to the wall. For this load balance to happen, any lateral load supported by the wall would have to be opposed by the pilaster floor attachment. This could be a great design, since no appreciable loads gets applied to the fasteners holding the brackets to the wall. The partition applies no shear load to the wall fasteners, so this design seems to have great advantages.
Unfortunately, the pilaster has some flexibility and the floor brackets have their own design limitations, so the whole partition assembly tends to slip over time. The actually load balance of the partition installation is closer to that shown in Figure 4, below.
Figure 4: Actual Partition Support Loads.
As the pilaster bends and the floor bracket slips, the load has to be balanced another way as shown in the figure. Unfortunately, this balance requires a small vertical load at each wall bracket (approximately ¼ the partition weight). If we look at just the wall bracket, it will become obvious why fasteners get pulled from the wall. Refer to Figure 5, below.
Figure 5: Original Partition Wall Bracket Loads.
Even with a fraction of the partition weight carried by the wall bracket, this translates into high fastener tension. The only way the bracket can keep from rotating is by putting the wall fasteners/anchors in tension. Since anchor pull-out strength in drywall this is the weakest part of the entire partition assembly, the anchors eventually pull from the wall and the bracket rotates to a position show in Figure 1.
A solution to this problem is to add another fastener in the bracket to carry the eccentric load. Since standard wall brackets vary in height from each manufacturer, a slot is used to pick up the original fastener locations. The second fastener is match drilled to the bracket for a perfect fit. Now the wall anchors only need to take shear loads, as shown in Figure 6 below.
Figure 6: Fix-a-Stall Wall Bracket Loads.
The Fix-a-Stall Wall Bracket also has a modular base that can accept hole locations in the wall used by any standard bracket (Figure 7, below).
Figure 7: Base of Fix-a-Stall Partition Wall Bracket Showing Modular Design (shown in Titanium Gray).
The original wall anchors are removed, the holes are enlarged to 5/16 inch, and new anchors are installed. Then, the closest of the three holes (Figure 7, left side) is used to attach the bracket to the wall. The other fastener is installed through the slot on the other side of the bracket (Figure 7, right side). This design keeps the bracket from sliding on the wall, even with loose fasteners.
Figure 8: Fix-a-Stall Partition Wall Bracket (show in Satin Silver).
I hope this article spreads new light onto the load paths of a partition installation. If you are installing new partitions using the standard wall brackets, you shown now recognize how important it is to secure the pilaster floor brackets properly. This will create load paths closer to those shown in Figure 3 and minimize the fastener prying.
If you have brackets that look like the one in Figure 1, and are trying to repair them as cost effectively as possible, while maintaining a professional look, the Fix-a-Stall Partition Repair Kit is a perfect choice. The finished installation is shown below (Figure 9).
Figure 9: Fix-a-Stall Wall Bracket Kit - Installed.
The brackets kits are available in 3 colors, Silver Satin, Titanium Gray or Ebony (black). Each kit comes with two brackets and all the hardware needed to repair one partition.
Figure 10: Fix-a-Stall Partition Repair Kit.
For more information, check out the Fix-a-Stall Partition Bracket Website Page.