This can be relatively complicated because of the type of equipment and whether this can be considered a one time expense or a capital investment in the business. As stated explicitly below, replacing equipment can be deducted, as long as it it not due to negligence on the part of the owner, but one would have to ask specifically if the depreciation of the original equipment should be considered as well as the expected lifetime of that equipment.
The concept of being a nine-tenths partner with Hashem can be used in this consideration.
This reminds me of the old joke about the original name of the clothing store that shows this concept. Hashem and Shneider which translates into English as a famous modern store
As we see in Deducting Expenses From Our Maaser Obligation
To quote Rabbi David Oppenheim (1664-1736. Author of Shaalos
U’Teshuvos Nishal L’Dovid. This quote can be found in Sefer Maaser
Kesafim, edited by Dr. Cyril Domb, page 61), “Regarding financial
Maaser, a person is a (9/10) partner with Hashem in his income. When
it comes to deducting expenses, a person may deduct any expenses or
losses that occur in his business as long as they are not due to his
negligence, for there is a mutual liability (between the business and
Maaser) …therefore any expenses incurred in earning the income,
including any clothing that must be purchased for a business related
journey, may be deducted”.
This concept of a person being a partner with Hashem has direct
ramifications on what expenses may be deducted from our income before
setting aside Maaser, and on the distribution of Maaser funds. We are
only going to discuss the former in this class.
Money spent by a person to enable him to earn an income, may be
deducted from his income before separating Maaser, even if it was used
for this purpose unsuccessfully. Any expenditures or losses that are
not for the purpose of producing more income are considered a person’s
private income, and Maaser must be separated from these funds.
In light of the above, the following may be deducted from the gross
income before separating Maaser by a self employed business owner:
Wages paid to an employee, any inventory related expenses, cost of
leasing property or vehicles, advertising, and any business related
Any financial loss caused by theft, loss, or broken machinery may also
be deducted, as long as it is not due to negligence on the business
However, if property or vehicles were purchased for the business, the
money used for this purpose is not considered a business expense,
rather it is a capital investment, and Maaser must be paid on it.
Depreciation of these items due to normal wear and tear may be
deducted. Obviously, the cost of maintaining these items may also be
See the Shaalos U’Teshuvos Shaar Ephraim (84), Chut HaShoni (90),
Shvus Yaaakov (Vol. 2 Siman 86), and Avkas Roechel (3). See also the
Pischei Teshuva (Yoreh De’ah 249:1), Nodeh B’Yehuda (Yoreh De’ah Vol.
2 Siman 199), Chavos Yair (224), and Ahavas Chessed (Vol. 2 18:2).