I’m getting ready to have a small concrete foundation (22″x4’8″) poured. It will be attached to my current foundation. I’m going to frame it and use it to hold a gas fireplace.
Do I need to do something for drainage for this new foundation?
I’m getting ready to have a small concrete foundation (22″x4’8″) poured. It will be attached to my current foundation. I’m going to frame it and use it to hold a gas fireplace.
Do I need to do something for drainage for this new foundation?
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Replies
This is just a simple pad, right? No thickened edges. In other words an appliance pad.
As long as water does not flow over the pad and get in the furnace you won't need drainage.
Some math;
furnace = 500#
Pad @ 22x56 = 8.55 sq ft
pad @ 3 1/2" thick ~430#
108.5# sq ft total soil loading.
For comparison, a 150# load (weight of average man) on a square chunk of 2x4 (3.5"x3.5") is a load of 1763# sq ft.
SamT
Soil Bearing Capacities
Load-Bearing Pressure
(pounds per square foot)
Sand, silty sand, clayey sand, silty gravel, and clayey gravel
Clay, sandy clay, silty clay, and clayey silt
Source: Table 401.4.1; CABO One- and Two- Family Dwelling Code; 1995.