Ask The Expert


Hi Robert,
I saw a concrete driveway that I would like to replicate at my house. There were little rocks, decorative pebble stones of all different colors, on the top that looked really nice. How do they achieve that look?

Thank you,
Jay H.

Hi Jay,
That is what we call exposed aggregate. I’ve always liked that look also. There are a couple of different ways to get that finish.
At a new pour, while the concrete is still wet, you broadcast the stone onto the surface. This is where timing and experience come into play. You would then trowel the stone, which gets it level and pushes it down and embeds it into the concrete and allows the cream to come up over the top. This is what you want. This causes that aggregate to get set into a good solid concrete base. Let that set for about 30 minutes.
Next, you put a release (a chemical) into a Hudson sprayer, and apply to the top of the concrete. This release will break up that top layer, the cream which is concealing the aggregate. After that sits for about 20 minutes, hose it down and the cream will wash away, exposing the aggregate underneath.
Dear Robert,
I have some rental properties and I have to have them re-keyed for each new tenant. I heard that it is possible to re-key the locks without going through a locksmith. I asked my locksmith and he said he had never heard of anything like this.

Thank you,
Lorna W.

Hi Lorna,
The Kwikset company has SmartKey technology.
Instead of traditional pins and tumblers, the SmartKey locks have a side locking bar, which helps to prevent against lock bumping and allows you to re-key your own locks.
First, you would insert the functioning key into the lock and turn it ¼ turn clockwise. Leaving that key in place, insert and remove the Kwikset “learning tool.” Then you would remove the functioning key and insert the new key. Turn the new key ¼ counter-clockwise and you’ve just re-keyed your lock.
According to Kwikset, these locks have passed the most rigorous lock-picking tests in the industry, the UL 437, and feature a heavy duty ANSI Grade 1 deadbolt.

Hi Mr. Lamoureux,
We have an underground parking garage and there is one spot that collects water. We heard about El Nino coming this year and we want to install drains. The contractor said since the slab was 18” thick, we needed to x-ray before installing the drains.

Thank you,
Jen G.

Hi Jen,
You have to x-ray before coring into concrete because there may be structural steel, conduit or post-tension cables running underneath that you do not want to cut through. Cutting through electrical conduit or PT cables can be deadly.
An 18” thickness only means the laboratory will have to use cobalt that penetrates from 12” to 36”. They use iridium on concrete less than 12” thick.
Just so you’ll know, all people and pets will have to be at least 75 feet away from the shot zone. Sometimes exceptions can be made and barricades can be put up but I would notify all residents that are within 75 that they must vacate their premises during the x-rays.

Submit your questions to: Robert Lamoureux of IMS Construction, Valencia, CA, has 30 years experience as a commercial General, Electrical and Plumbing contractor. The opinions expressed in “Ask the Expert” are not to replace the recommendations of a qualified contractor after a thorough visual inspection has been made.

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