Question
I want to begin a small shrub and hedge removal business. I intend to use my pick-up truck (91 Toyota) to rip them out, but what concerns should I have in approaching this type of work in this manner.

Do I have to worry about doing damage to underground pipes & such, or possibly damage to a foundation if the roots are next to the house?

What I mean is, can the roots make their way into the foundation wall or pipes, and can the weight of my truck do damage to pipes?

Are there certain shrubs and hedges I should NOT pull out due to the root system being too strong for my truck?

Also, in the event there are shrubs & hedges that are not possible for me to pull out due to an obstacle, what is the next best option?

Answer
Nick, three things come to my mind regarding tree/shrub removal.  

Damage to underground pipes and utilities are an unfortunate by-product of this type of work.  Be up-front with the homeowner BEFORE the task that this is a possibility, so they are not in the dark (literally & figuratively) when you yank their underground power-line up with the shrub roots firmly attached.

ALWAYS call the underground service locator in your area.  It is free in most areas; you just need to give them a few days lead-time.  They are a clearinghouse for locating underground utilities that might be in the way - Especially if the trees/shrubs are near roadways.  Call the local utility company for your region's service number.  Our local service cooperates with probably 10 different cities, counties, and utility providers.  

Don't forget that your '91 pick-up can also smash more delicate stuff, too, like sprinkler systems and concrete patios/walks.  They'll come up as well, when you don't prepare the shrub for removal by cutting the roots from the area that you want left un-damaged.

Damage to foundations is another problem - and yes, roots can crack a foundation.  I'd say it is a "case-by-case" kind of deal, where you'll just have to evaluate the situation and let the homeowner know what could happen BEFORE, you start breaking stuff.  Plus, when you don't break anything, you'll be the hero.

As to types of shrubs you should not pull up using this method, there are probably a few, like some willows or juniper.  The desert plants are usually the toughest - Russian olive, Sagebrush, Cotoneaster...IF they are drought-tolerant, there is a reason why!  Deep, nasty roots.

I'd say that if you start yanking, and the whole area starts to heave, its time to cut the roots out, using shovels and picks before trying again with the truck. I've pulled shrub & tree stumps, but it is unpleasant work. Lots of hogging out, then chains and back-strength (or truck-strength).  You said you'd be doing just shrubs, so maybe it will be less strenuous.  Some just pop right out like Pez candies, and others have a hold on the earth like a two-year old and his teddy bear.

Other methods include just cutting the shrub off at the ground using a chain saw, and leaving the roots to rot away, or for the bigger shrubs and trees, grinding the roots out using a stump grinder.  You can speed up the rotting process using chemical "stump removers", available at the local Big Box chain (Wal-Mart/K-Mart/Home Depot/Lowes, etc.)

Finally, I'd get some liability insurance.   You've probably seen folks advertise that they are "licensed and insured" - it is a good idea to follow their lead on this.

All the best ~M