Bluestone Path damage from roof drain - Contractor Talk - Professional Construction and Remodeling Forum

Jamboy · 04-30-2009, 08:48 AM

I am hoping someone has an idea of the effect roof drainage would have on a mortared Bluestone pathway by directed roof drainage. The pathway encloses a garden where the downspout discharges. The subsoil is clay which pretty much eliminates the possibility of using a dry well. I was hoping to use a pop-emitter or angled outlet that would have to run across the pathway onto an established lawn.

The customer lives in Maryland in the 3" or 3.5" 100-year rain zone. The roof is about 300 sq. ft. The Bluestone is mortared between the joints and is on a bed of mortar and a sub-base that appears to go below the frost line (No problems from ground heave, yet).

Will this setup have a an effect on the integrity of the walkway? I realize the quality of the workmanship is a factor but assuming a decent job was done, what may happen and when? Without actually seeing the setup, any general ideas would be very helpful.

Jamboy

raskolnikov · 04-30-2009, 07:42 PM

JB,
I just this week went back to a large project I did in '96 for a few small repairs. The owners also wanted us to run some under patio runs for leaders that dumped on wet laid work that pitched as needed. We're in N.E. and water and freezing and moss and pollin and dirt and not maintaining and dogs and kids and... What seemed like an okay way of losing the water wasn't. IMHO if you can lose the water without flooding the masonry in the long run the client will smile on you! And not just call you back for repairs.

D.

dakzaag · 04-30-2009, 10:15 PM

To quote a popular radio personality in Chicago, "Water always wins"

Here is a pic of what happens when water comes off a roof and hits the brick on the side of a house. Unfortunately I did not take before pics, but let me just say the brick were eroded down to visible mortar in the holes.

about $10,000 later we had the house looking like this

water was coming off the second story roof and then bouncing off the porch roof and had the brick gone half way to the ground. HO was a little slow in addressing gutter/downspout issues.

It actually looks better than the picture shows. When you pull up to the house, you have to study the brick to see the repair.

Here is another corner on same house

For good measure the guy mixing the mud was the HO (25 yrs ago.) He distinctly remembers mixing 2:1 sand to mortar. The mortar was very hard, we beat our brains out on that wall about 18 months ago.

Went back just last week to do a few minor repairs you can see in the first pic. New helper couldn't see the new brick til I pointed it out. But then again he does not notice an empty mud board until it hits him in the head.